Update argparse to get multiline alignment

thirdparty/argparse/samples/optional_flag_argument.cpp

@@ -15,7 +15,7 @@ int main(int argc, char *argv[]) {
   } catch (const std::runtime_error &err) {
     std::cerr << err.what() << std::endl;
     std::cerr << program;
-    std::exit(1);
+    return 1;
   }
 
   if (program["--verbose"] == true) {