removed compiler warning in main.cpp

src/main.cpp

@@ -6,7 +6,7 @@
 #include <core/engine.hpp>
 #include <util/stacktrace.hpp>
 
-int main(int argc, char* argv[]) {
+int main(int, char* argv[]) {
     try {
         gdw::initStacktrace(argv[0]);
 		gdw::engine e;