Cannot stream files with spaces over http

Trying to play a file over http with a space in the filename fails. Manually replacing the spaces with %20 also does not work.

Workaround:

In the function GSTPlayer.play add:

if uri.startswith("http://"):
  uri = uri.replace(' ', '%20')

Also note that the the same function also replace all occurences of % with %25, which will break all uris with "escaped" special characters in it.