Fixed CLANG_ENABLE_CODE_COVERAGE flag so release can be made

AFNetworking.xcodeproj/project.pbxproj

@@ -1223,6 +1223,7 @@
 				ALWAYS_SEARCH_USER_PATHS = NO;
 				CLANG_CXX_LANGUAGE_STANDARD = "gnu++0x";
 				CLANG_CXX_LIBRARY = "libc++";
+				CLANG_ENABLE_CODE_COVERAGE = YES;
 				CLANG_ENABLE_MODULES = YES;
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_ASSIGN_ENUM = YES;
@@ -1297,6 +1298,7 @@
 				ALWAYS_SEARCH_USER_PATHS = NO;
 				CLANG_CXX_LANGUAGE_STANDARD = "gnu++0x";
 				CLANG_CXX_LIBRARY = "libc++";
+				CLANG_ENABLE_CODE_COVERAGE = NO;
 				CLANG_ENABLE_MODULES = YES;
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_ASSIGN_ENUM = YES;