Having installed a new v1.5 wiki, I found that over 30 messages on
Special:Allmessages were highlighted in pink/green. The two versions of these
messages appear identical, but are nonetheless being marked as different.

As well as several hard-to-check messages (e.g. Monobook.js) this applies to
various short messages, such as alreadyloggedin, historywarning and
ip_range_invalid which are short enough to easily see that the two versions of
the message are the same.

Expected behaviour: No messages would be highlighted, as no text has been
changed from the default.

Version: 1.5.x
Severity: trivial