Release process: improve instructions for updating PO files for our custom packages.

It makes little sense to "correct any displayed error" so don't expect the RM to
do it. Also, commit only once the PO files have been checked + automate
this step.

wiki/src/contribute/release_process.mdwn

@@ -203,13 +203,18 @@ Transifex branches of `git://git.torproject.org/translation.git` (e.g.
 `whisperback_completed`) instead. In this case, skip PO files for
 [[translation teams that use Git|contribute/how/translate#translate]].
 
-Add and commit.
-
 Then check the PO files:
 
 	"${RELEASE_CHECKOUT:?}"/submodules/jenkins-tools/slaves/check_po
 
-Correct any displayed error, then commit the changes if any.
+… and `git rm` the PO files that have issues (alternatively, if you
+feel like it you can fix them but your changes will be overwritten
+next time we import translations from Transifex).
+
+And finally, commit:
+
+    git commit po \
+	    -m "Update POT and PO files, pull updated translations from Transifex."
 
 Then see the relevant release processes, and upload the packages to
 the release branch's custom APT suite: