autosupport: Fix bashism.

'==' is bashism (bashspecific, fails when dash is /bin/sh). Anyway, a
'case' works better there.

Originally committed in r375059 and r375060 on 2012-10-16 21:13:08.

ASTERISK-20567 #close
Reported by: Tzafrir Cohen


git-svn-id: http://svn.asterisk.org/svn/asterisk/branches/11@424117 f38db490-d61c-443f-a65b-d21fe96a405b