Fix pattern match for translations

Fix the pattern match so that the if condition matches files
ending with ".po"

Change-Id: I69aea5703438fa354a7ec4a7d4ec578fc7d631cb

modules/openstack_project/files/slave_scripts/common_translation_update.sh

@@ -268,7 +268,8 @@ function filter_commits ()
     PO_CHANGE=0
     for f in `git diff --cached --name-only`
     do
-        if [[ $f =~ "\.po$" ]] ; then
+        # Check for all files endig with ".po"
+        if [[ $f =~ .po$ ]] ; then
             PO_CHANGE=1
         fi
         # It's ok if the grep fails