Sort PO files to avoid random reorder

Changes like
https://review.openstack.org/#/c/185848/1/horizon/locale/ca/LC_MESSAGES/djangojs.po
just reordered entries with no content change. Pass --sort-output to
msgattrib to filter the entries in alphabetical order so that any
rearrangements of the source files will not have an effect on the order
of the entries.

Change-Id: I2d9c91f3d1fbcf61ae21521758836793742389ed

jenkins/scripts/common_translation_update.sh

@@ -397,7 +397,8 @@ function compress_po_files {
     local directory=$1
 
     for i in `find $directory -name *.po `; do
-        msgattrib --translated --no-location "$i" --output="${i}.tmp"
+        msgattrib --translated --no-location --sort-output "$i" \
+            --output="${i}.tmp"
         mv "${i}.tmp" "$i"
     done
 }
@@ -417,7 +418,8 @@ function compress_manual_po_files {
                 continue
             fi
         fi
-        msgattrib --translated --no-location "$i" --output="${i}.tmp"
+        msgattrib --translated --no-location --sort-output "$i" \
+            --output="${i}.tmp"
         mv "${i}.tmp" "$i"
     done
 }
@@ -435,7 +437,8 @@ function compress_non_en_po_files {
         if [[ $i =~ "/locale/en/LC_MESSAGES/" ]] ; then
             continue
         fi
-        msgattrib --translated --no-location "$i" --output="${i}.tmp"
+        msgattrib --translated --no-location --sort-output "$i" \
+            --output="${i}.tmp"
         mv "${i}.tmp" "$i"
     done
 }