Fix some i18n/GENDER issues spotted by Protnet

* https://translatewiki.net/wiki/Thread:Support/About_MediaWiki:Usermerge-userdeleted
* https://translatewiki.net/wiki/Thread:Support/About_MediaWiki:Usermerge-success
* https://translatewiki.net/wiki/Thread:Support/About_MediaWiki:Usermerge-success-log
* https://translatewiki.net/wiki/Thread:Support/About_MediaWiki:Usermerge-noselfdelete
* https://translatewiki.net/wiki/Thread:Support/About_MediaWiki:Usermerge-protectedgroup

Change-Id: I4e434697a31585030ea584b54399c5fcc1eed960