Remove unused xmessage from deps; correct arch

Having taken a look at the PKGBUILD recently, I believe these minor improvements can be made:

• Remove xorg-xmessage from depends

  The source code only references xmessage followed by w_die to inform users that it's incapable of doing certain tasks. The xmessage command is never invoked. Besides, the winetricks_detect_gui function only cares about zenity & kdialog.

• Change arch from x86_64 to any

  winetricks is written in pure POSIX sh. It's totally architecture independent.