Remove fallback from Persian to Arabic (update from compat)

As a Persian I need to say, Arabic and Persian just have the writing system in common and even they belong to different lingual groups.fa belongs to Indio-Europian and Arabic is Semetic. Returning to Arabic when fa message doesn't exists make Persian people angryBecaue they don't like to be mistaken as Arabs and this retuning has no advantage for Persian, Persians know English better than Arabic

https://gerrit.wikimedia.org/r/#/c/93025/

Change-Id: Iac4534c72bfc0b66959eba5442d882f4244f7c9c
Merge "Remove fallback from Persian to Arabic (update from compat)"