Fixed conflicting mains for mingw build

.appveyor.yml

@@ -61,7 +61,7 @@ build_script:
   # Build
   - |-
     cmake --version
-    cmake -DCMAKE_PREFIX_PATH="%PREFIX%" -DCMAKE_C_COMPILER=mingw32-gcc.exe -DCMAKE_CXX_COMPILER=mingw32-c++.exe -DCMAKE_MAKE_PROGRAM=mingw32-make.exe -DCMAKE_VERBOSE_MAKEFILE=ON -DSTANDALONE=ON -DCMAKE_INSTALL_PREFIX="C:\breakhack" -G "MinGW Makefiles"
+    cmake -DCMAKE_PREFIX_PATH="%PREFIX%" -DCMAKE_C_COMPILER=mingw32-gcc.exe -DCMAKE_MAKE_PROGRAM=mingw32-make.exe -DCMAKE_VERBOSE_MAKEFILE=ON -G "MinGW Makefiles"
 
   - |-
     mingw32-make

src/main.c

@@ -187,8 +187,11 @@ void close(void)
 	SDL_Quit();
 }
 
-int main(void)
+int main(int argc, char *argv[])
 {
+	UNUSED(argc);
+	UNUSED(argv);
+
 	if (!init())
 		return 1;