Fix usage of the broargs broctl option

Fixed a problem that would occur when a command-line argument in broargs
contained a space (and the user quoted the argument correctly in broctl.cfg).
The problem was that the shell scripts that run bro were splitting the
argument into separate arguments (due to the embedded space character).

This example broctl.cfg should now work correctly:
broargs = --filter 'not ip6'
Fix another usage of the broargs broctl option

This change should have been included in the previous commit.
Merge remote-tracking branch 'origin/master' into topic/dnthayer/broargs
Merge remote-tracking branch 'origin/topic/dnthayer/broargs'

BIT-1084 #merged

* origin/topic/dnthayer/broargs:
  Fix another usage of the broargs broctl option
  Fix usage of the broargs broctl option
Merge branch 'master' of git.bro-ids.org:broctl