Windows: Fix compile error: cast from 'HINSTANCE' to 'int' loses precision

src/modules/system/System.cpp

@@ -164,7 +164,7 @@ bool System::openURL(const std::string &url) const
 
 #endif
 
-	return (int) result > 32;
+	return (ptrdiff_t) result > 32;
 
 #endif
 }