Make debian init script conform to the LSB standard

Previously, this init script would return 1 if Asterisk was already running.
This is incorrect behavior according to the LSB standard and has been fixed by
returning 0 instead.

(closes issue ASTERISK-17958)
Reported-by: johnc
........

Merged revisions 349529 from http://svn.asterisk.org/svn/asterisk/branches/1.8


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/10@349532 65c4cc65-6c06-0410-ace0-fbb531ad65f3

contrib/init.d/rc.debian.asterisk

@@ -69,7 +69,7 @@ case "$1" in
 	VERSION=`${DAEMON} -rx 'core show version' || ${TRUE}`
 	if [ "`echo $VERSION | cut -c 1-8`" = "Asterisk" ]; then
 		echo "Asterisk is already running.  $0 will exit now."
-		exit 1
+		exit 0
 	fi
 
 	log_begin_msg "Starting $DESC: $NAME"