Use login-throttled properly everywhere

Actually proper usage would probably be to split the messages.
Followup to Id385be840f340476fbe7a818ff1d05154fe86d68;
spotted by Shirayuki.
https://translatewiki.net/wiki/Thread:Support/About_MediaWiki:Login-throttled/en

Change-Id: I565971a90fc383327a51d717a80013cb7a3e9c9b