(bug 49354) New config variable: $wgNoticeUseLanguageConversion

This setting disables variant languages and use an automatically
converted version of banners fetched from their parent language
(zh for zh-cn, for example) instead.

Bug: 49354
Change-Id: I16292800b857c681e0ed54a221cd4c4e5def91b5
Merge "(bug 49354) New config variable: $wgNoticeUseLanguageConversion"