Quassel IRC

IRCnet servers advertise the following parameters: PREFIX=(ov)@+ CHANTYPES=#&!+

Since PREFIX and CHANTYPES are not disjunctive on those servers, CoreBasicHandler::displayMsg() removes accidently the "+" from some channel names (e.g. "+linux.de"), leaving "linux.de" as target, which is, of course, not recognized as a valid channel name. As a result PRIVMSG in such channels are not displayed in the channel's buffer. Still they trigger notifications.

I have modified CoreBasicHandler::displayMsg() to check, if the removal of an alleged prefix leads to an invalid channel name. Nevertheless, since I do not know the IRC protocol very well, this may brake some other features. A patch is included.