Change the autonym of Manipuri to Meetei script
Meetei Mayek script is the one used in schools in Manipur
(see the Wikipedia article [[Meitei script]] for references).
It is also the script that is used for all the translations
in translatewiki [1] and for all the test articles
in the Wikimedia Incubator.[2]
[1] https://translatewiki.net/w/i.php?title=Special:Translate&filter=translated&group=mediawiki&language=mni&action=translate
[2] https://incubator.wikimedia.org/wiki/Special:PrefixIndex/wp/mni
Corresponding commit in language-data:
https://github.com/wikimedia/language-data/pull/57
Change-Id: I892320f2dfaac05bfc2a544502823a244a9ad1c8