Fix condition for find_dependency(GLib2) (FluidSynth#1673)

Author: dg0yt

FluidSynthConfig.cmake.in

@@ -74,7 +74,7 @@ if(NOT FLUIDSYNTH_IS_SHARED)
     find_dependency(Threads)
   endif()
 
-  if(FLUIDSYNTH_SUPPORT_GLIB AND NOT TARGET GLib2::glib-2 OR NOT TARGET GLib2::gthread-2)
+  if(FLUIDSYNTH_SUPPORT_GLIB AND (NOT TARGET GLib2::glib-2 OR NOT TARGET GLib2::gthread-2))
     find_dependency(GLib2 @GLIB2_MINUMUM_VERSION@)
   endif()