- fixed xcode bundle identifier warning

warning: User-supplied CFBundleIdentifier value 'org.drdteam.gzdoom' in the Info.plist must be the same as the PRODUCT_BUNDLE_IDENTIFIER build setting value ''.

src/CMakeLists.txt

@@ -1406,6 +1406,7 @@ if( APPLE )
 	set_target_properties(zdoom PROPERTIES
 		LINK_FLAGS "${LINK_FRAMEWORKS}"
 		MACOSX_BUNDLE_INFO_PLIST "${CMAKE_CURRENT_SOURCE_DIR}/posix/osx/zdoom-info.plist"
+		XCODE_ATTRIBUTE_PRODUCT_BUNDLE_IDENTIFIER "org.drdteam.gzdoom"
 		XCODE_ATTRIBUTE_CODE_SIGN_IDENTITY "" )
 
 	# Dymanic libraries like libvulkan.dylib or libMoltenVK.dylib will be loaded by dlopen()