Declare main() with argc/argv params in tests

Declaring the main method as "int main(void)" causes issues with SDL.

Fixes #1209 <https://github.com/Genymobile/scrcpy/issues/1209>

app/tests/test_strutil.c

@@ -286,7 +286,10 @@ static void test_parse_integer_with_suffix(void) {
     assert(!ok);
 }
 
-int main(void) {
+int main(int argc, char *argv[]) {
+    (void) argc;
+    (void) argv;
+
     test_xstrncpy_simple();
     test_xstrncpy_just_fit();
     test_xstrncpy_truncated();