fmClient segfaults on short string parameter

Same thing happens with -c option:

$ fmClientCli -c 23
terminate called after throwing an instance of 'std::out_of_range'
  what(): basic_string::substr
Aborted (core dumped)

Seems the bug can be here:
https://github.com/openstack/stx-fault/blob/master/fm-common/sources/fmAlarmUtils.cpp#L205

static void str_to_vector(const std::string &s, std::vector<std::string> &alarm) {
 size_t offset = 0;
 alarm.clear();
 while (true) {
  size_t beg = (offset==0) ? 0 : s.find("###",offset);
  if (beg==std::string::npos) break;
  size_t e = s.find("###",beg+3);
  std::string cont = s.substr(beg+3,e-(beg+3));
  alarm.push_back(cont);
  offset=e;
 }
}

Minor issue; not release gating, but would be nice to fix.
This would be a good training opportunity for someone ramping up on the fault flock component.

Fix proposed to branch: master
Review: https://review.openstack.org/633151

Reviewed: https://review.openstack.org/633151
Committed: https://git.openstack.org/cgit/openstack/stx-fault/commit/?id=64939761628c1bf2b389877bfd1618f8d1dfba65
Submitter: Zuul
Branch: master

commit 64939761628c1bf2b389877bfd1618f8d1dfba65
Author: Shuicheng Lin <email address hidden>
Date: Sat Jan 26 01:19:38 2019 +0800

    fix issue: fmClient segfaults on short string parameter

    It is due to out of range access violation. Fix it by checking length
    before access.

    Closes-Bug: 1807986

    Change-Id: Iba2b445f50fd98a74d932c9b3f691fc7145274bb
    Signed-off-by: Shuicheng Lin <email address hidden>

Adding stx.2019.05 tag as this fix was merged for that release