Error in system information after logging in to your account

[Impact]

 * An error message is included in when rendering landscape-sysinfo
   statistics through pam_motd if there are processes with a non-ascii
   command. This is due to the fact that environment is not passed
   by pam-motd.

 * As landscape-sysinfo is present on cloud-images, this bug affects
   all images since bionic.

 * This change sets locale variables in the landscape-sysinfo wrapper,
   so the python interpreter can know which locale to load.

[Test Case]

 * Make sure the system default locale is configured with a valid
   charset (e.g. /etc/default/locale contains "LANG=C.UTF-8").

 * Spawn a process with non-ascii parameters (which are part of the
   configured charset): sh -c 'sleep 60; echo holà mundo' & sudo login

 * Check the output of the motd

[Regression Potential]

 * Since this changes only alters the landscape-sysinfo wrapper script,
   its effects shouldn't alter other functionalities.

 * Although it is still possible to have a misconfigured locale file,
   and run commands, the effect would be limited to an error message
   similar to the one which is currently displayed.

[Original Description]

Exception after login:
---------------------
Welcome to Ubuntu 18.04 LTS (GNU/Linux 4.15.0-24-generic x86_64)

 * Documentation: https://help.ubuntu.com
 * Management: https://landscape.canonical.com
 * Support: https://ubuntu.com/advantage

  System information as of Wed Jul 4 10:41:09 CEST 2018

  System load: 0.0 Swap usage: 5%
  Usage of /home: unknown Users logged in: 0
  Memory usage: 16% IP address for enp3s0: 192.168.20.12

  => There were exceptions while processing one or more plugins. See
     /var/log/landscape/sysinfo.log for more information.

 * Meltdown, Spectre and Ubuntu: What are the attack vectors,
   how the fixes work, and everything else you need to know
   - https://ubu.one/u2Know

 * Canonical Livepatch is available for installation.
   - Reduce system reboots and improve kernel security. Activate at:
     https://ubuntu.com/livepatch

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0 aktualizacji jest aktualizacjami zabezpieczeń.
--------------------

sysinfo.log:

2018-06-19 23:19:34,877 ERROR Processes plugin raised an exception.
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/landscape/sysinfo/sysinfo.py", line 99, in run
    result = plugin.run()
  File "/usr/lib/python3/dist-packages/landscape/sysinfo/processes.py", line 18, in run
    for process_info in info.get_all_process_info():
  File "/usr/lib/python3/dist-packages/landscape/lib/process.py", line 39, in get_all_process_info
    process_info = self.get_process_info(process_id)
  File "/usr/lib/python3/dist-packages/landscape/lib/process.py", line 61, in get_process_info
    cmd_line = file.readline()
  File "/usr/lib/python3.6/encodings/ascii.py", line 26, in decode
    return codecs.ascii_decode(input, self.errors)[0]
UnicodeDecodeError: 'ascii' codec can't decode byte 0xc5 in position 152: ordinal not in range(128)

-----------------
the problem concerned the decoding of utf8 forms, attached patch resolve my problem, after patch my login
screen looks normal:

-----------------
Welcome to Ubuntu 18.04 LTS (GNU/Linux 4.15.0-24-generic x86_64)

 * Documentation: https://help.ubuntu.com
 * Management: https://landscape.canonical.com
 * Support: https://ubuntu.com/advantage

  System information as of Wed Jul 4 11:10:20 CEST 2018

  System load: 0.2 Processes: 187
  Usage of /home: unknown Users logged in: 1
  Memory usage: 18% IP address for enp3s0: 192.168.20.12
  Swap usage: 5%

 * Meltdown, Spectre and Ubuntu: What are the attack vectors,
   how the fixes work, and everything else you need to know
   - https://ubu.one/u2Know

 * Canonical Livepatch is available for installation.
   - Reduce system reboots and improve kernel security. Activate at:
     https://ubuntu.com/livepatch

0 pakietów może zostać zaktualizowanych.
0 aktualizacji jest aktualizacjami zabezpieczeń.