Fixed crash at saving if command gives no output

source/ubl-settings-services.c

@@ -7,9 +7,13 @@ config main_config;
 void on_save_done(main_window *widgets, config_str output, int size){
     if (widgets) {};
 	char *final_output = yon_char_parsed_to_string(output,size,"");
-	printf("%s\n",final_output);
-	free(final_output);
-	yon_char_parsed_free(output,size);
+    if (!yon_char_is_empty(final_output)){
+        printf("%s\n",final_output);
+        free(final_output);
+    }
+    if (output&&size>0){
+        yon_char_parsed_free(output,size);
+    }
     textdomain(template_ui_LocaleName);
 	switch (main_config.save_config){
 		case 0: