Fixed grep: IRC is not always in capitals

With grep IRC there is not output from cat on the log file but with grep -i irc there is, see e.g.

$ cat master/twistd.log | grep IRC
$ cat master/twistd.log | grep -i irc
2013-04-15 13:26:44+0200 [-] Starting factory <buildbot.status.words.IrcStatusFactory instance at 0x26ab638>
2013-04-15 13:26:58+0200 [IrcStatusBot,client] <buildbot.status.words.IrcStatusBot instance at 0x23ea4d0>: I have joined #buildbot-test
2013-04-15 13:27:29+0200 [-] Starting factory <buildbot.status.words.IrcStatusFactory instance at 0x26b8170>
2013-04-15 13:27:29+0200 [IrcStatusBot,client] not scheduling reconnection attempt
2013-04-15 13:27:29+0200 [IrcStatusBot,client] Stopping factory <buildbot.status.words.IrcStatusFactory instance at 0x26ab638>
2013-04-15 13:27:42+0200 [IrcStatusBot,client] <buildbot.status.words.IrcStatusBot instance at 0x25a10e0>: I have joined #buildbot-test

Thus, maybe the example line from the log should be changed too?