userpref: Remove obsolete dict item check as plist_dict_set_item() takes care
userpref: Remove obsolete dict item check as plist_dict_set_item() takes care

kalev/libimobiledevice,libimobiledevice/libimobiledevice,libimobiledevice/libimobiledevice,libimobiledevice-win32/libimobiledevice,Tatsh/libimobiledevice,libimobiledevice-win32/libimobiledevice,libimobiledevice-win32/libimobiledevice,Tatsh/libimobiledevice,patweb/libimobiledevice,kalev/libimobiledevice,upbit/libimobiledevice,Tatsh/libimobiledevice,libimobiledevice-win32/libimobiledevice,patweb/libimobiledevice,patweb/libimobiledevice,Tatsh/libimobiledevice,upbit/libimobiledevice,upbit/libimobiledevice,kalev/libimobiledevice