Do not run unneeded update_catalog

update_catalog updates the po translation files from our pot file. Since
we only push the pot file, the changes to pot files are completely ignored
and can be removed.

Note that the other two upstream scripts (for horizon and manuals)
already do not update the po files.

Change-Id: Ib73405fa86fd96261030a98c18a6c8b628052c91
Merge "Do not run unneeded update_catalog"