Bug #1270

- The 'undo' command is now properly removing backlog entries.

src/es-ES.h

@@ -848,6 +848,7 @@
 #define STRING_TDB2_UNDO_COMPLETE    "Deshacer completado."
 #define STRING_TDB2_MISSING_TASK     "Tarea con UUID {1} no encontrada en los datos."
 #define STRING_TDB2_UNDO_IMPOSSIBLE  "No es posible deshacer."
+#define STRING_TDB2_UNDO_SYNCED      "Cannot undo change because the task was already synced.  Modify the task instead."
 
 // text
                                      // Se añade al final una lista de comandos separados por comas.