Command line parsing for remote debugging incorrect

https://github.com/qt-creator/qt-creator/blob/f36f04debabcf839a50c73e47202b24527e89ece/src/plugins/debugger/debuggerplugin.cpp#L1191

The above line should read more like (maybe do some validation on "val")

 remoteChannel = val;

As written the channel parameter of the debugger when passed via the command line is ignored. This breaks attaching to a remote debugger from the command line.