Fix broken handling of newusers/create2 events

[Krinkle]

It seems the pattern for these log message has changed at some point in 2009 and the logs have been full of errors about them since.

# Project.cs

            rCreate2Regex = new Regex( namespaces["2"]+@":(.*): \[\[" );

# RCReader.cs
                                 Match mc2 = ((Project)Program.prjlist[rce.project]).rCreate2Regex.Match(rce.comment);

Example of actual irc.wikimedia.org entries:

# 2016-11-02 on #nl.wikipedia

[[Speciaal:Log/newusers]] create2  * BRPots *  created new account Gebruiker:BRPwiki: eerder fout gemaakt

# 2016-11-02 on #nl.wikipedia
[[Speciaal:Log/newusers]] create2  * Sherani koster *  created new account Gebruiker:Rani farah koster

# 2017-10-13 on #en.wikipedia:
[[Special:Log/newusers]] create2  * Ujju.19788 *  created new account User:Upendhare

The MediaWiki legacy-irc message for this is newuserlog-create2-entry which contains:

created new account $1

This was changed in 2009 (diff), before that it was:

created account for $1

I guess it the user name used to be wrapped in [[ and ]], but is no longer. This makes it slightly more difficult to extract given that the log comment is also optional and appended right after an (optional) colon after the username. But I guess colons are illegal in usernames so changing the pattern as follows should work.

-            rCreate2Regex = new Regex( namespaces["2"]+@":(.*): \[\[" );
+            rCreate2Regex = new Regex( namespaces["2"]+@":([^]:+)" );