Add gig player to win32 builds

Gig player was missing a dll during the package process.  This fixes it.

src/CMakeLists.txt

@@ -175,6 +175,7 @@ IF(LMMS_BUILD_WIN32)
 					"${MINGW_PREFIX}/bin/libfluidsynth.dll"
 					"${MINGW_PREFIX}/bin/libfftw3f-3.dll"
 					"${MINGW_PREFIX}/bin/libFLAC-8.dll"
+					"${MINGW_PREFIX}/bin/libgig-6.dll"					
 					"${MINGW_PREFIX}/bin/libportaudio-2.dll"
 					"${MINGW_PREFIX}/lib/libsoundio.dll"
 					"${MINGW_PREFIX}/bin/libpng16-16.dll"