ios: set compilation mode to "wholemodule" for release builds

ios/app/app.xcodeproj/project.pbxproj

@@ -905,6 +905,7 @@
 				IPHONEOS_DEPLOYMENT_TARGET = 10.0;
 				MTL_ENABLE_DEBUG_INFO = NO;
 				SDKROOT = iphoneos;
+				SWIFT_COMPILATION_MODE = wholemodule;
 				VALIDATE_PRODUCT = YES;
 			};
 			name = Release;