fix a mistake of "V3 multisampling support cocos2d#18632" (cocos2d#18674)

Author: drelaptop

templates/cpp-template-default/proj.ios_mac/ios/RootViewController.mm

@@ -49,8 +49,8 @@ - (void)loadView {
                                          depthFormat: cocos2d::GLViewImpl::_depthFormat
                                   preserveBackbuffer: NO
                                           sharegroup: nil
-                                       multiSampling: cocos2d::GLViewImpl::_multisamling
-                                     numberOfSamples: cocos2d::GLViewImpl::_samples ];
+                                       multiSampling: cocos2d::GLViewImpl::_multisamplingCount > 0 ? YES : NO
+                                     numberOfSamples: cocos2d::GLViewImpl::_multisamplingCount ];
 
     // Enable or disable multiple touches
     [eaglView setMultipleTouchEnabled:NO];