* mu.c: free the config option (small leak fix)

src/mu.c

@@ -237,6 +237,7 @@ main (int argc, char *argv[])
 	
 	mu_msg_gmime_uninit();
 	mu_log_uninit();
+	mu_config_uninit(&config);
 	
 	return rv == MU_OK ? 0 : 1;
 }