Arguments parsing exception

[mohierf]

With some bad arguments, an exception is raised but not catched:

==> /usr/local/var/log/alignak/pollerd.log <==
[2017-05-15 07:54:53 CEST] ERROR: [alignak.module.nrpe-booster] Got an unhandled exception: invalid literal for int() with base 10: '-u'
Traceback (most recent call last):
  File "/usr/local/lib/python2.7/dist-packages/alignak_module_nrpe_booster-0.3.1-py2.7.egg/alignak_module_nrpe_booster/nrpe_booster.py", line 665, in work
    self.do_work(s, returns_queue, c)
  File "/usr/local/lib/python2.7/dist-packages/alignak_module_nrpe_booster-0.3.1-py2.7.egg/alignak_module_nrpe_booster/nrpe_booster.py", line 700, in do_work
    self.launch_new_checks()
  File "/usr/local/lib/python2.7/dist-packages/alignak_module_nrpe_booster-0.3.1-py2.7.egg/alignak_module_nrpe_booster/nrpe_booster.py", line 579, in launch_new_checks
    args = parse_args(clean_command[1:])
  File "/usr/local/lib/python2.7/dist-packages/alignak_module_nrpe_booster-0.3.1-py2.7.egg/alignak_module_nrpe_booster/nrpe_booster.py", line 469, in parse_args
    timeout = int(a)
ValueError: invalid literal for int() with base 10: '-u'