Don't disable-wireshark if your are going to build with QT

I tried to install Wireshark with Qt via `brew install --with-qt wireshark`, however the wireshark binary doesn't actually install (the command line binaries do).

On inspection of the formula, it appears that unless you also provide the `with-x` option when specifying `with-qt`, the fomula will exclude the wireshark binary.

i.e. build.with = 'qt' so
```
37:     args << "--disable-wireshark" << "--disable-gtktest" unless build.with? "x"
38:     args << "--with-qt" if build.with? "qt"
```
Line 37 sets the '--disable-wireshark' command so wireshark won't be built at all, regardless of whether we want it to build with QT.  X11 is not required to build with QT.

This is a crude change that will not disable wireshark if build.with equals 'x' or 'qt'  since I don't code Ruby.  Someone could express this more cleanly if they desire.