macosx/framework: Switch to C99.

VLCKit.xcodeproj/project.pbxproj

@@ -603,6 +603,7 @@
 				DYLIB_COMPATIBILITY_VERSION = 1;
 				DYLIB_CURRENT_VERSION = 1;
 				FRAMEWORK_VERSION = A;
+				GCC_C_LANGUAGE_STANDARD = c99;
 				GCC_DYNAMIC_NO_PIC = NO;
 				GCC_ENABLE_FIX_AND_CONTINUE = YES;
 				GCC_ENABLE_OBJC_EXCEPTIONS = YES;