Remove interrobang (‽) from centralnotice-delete-banner-title

No use is known outside English and informal style is not appropriate
or consistent with the messaging of CentralNotice.
https://translatewiki.net/wiki/Thread:Support/About_MediaWiki:Centralnotice-delete-banner-title/ko

Change-Id: I86f328d7c3f955f4f65c6182782d80a9c9b783ce
Merge "Remove interrobang (‽) from centralnotice-delete-banner-title"