Minor: removed typo.

worker.h

@@ -224,7 +224,9 @@ class Worker : public QThread{
                 QStringList lst = m_worker->m_ismasTriggerStatusMessage;
                 UPDATE_STEP last = m_worker->m_lastFailedUpdateStep;
                 if (m_worker->smap.contains(last)) {
-                    lst << QString(" (last failed: %1)").arg(m_worker->smap[last]);
+                    lst << QString(" (last failed step: %1)").arg(m_worker->smap[last]);
+                } else {
+                    lst << QString(" (last failed step unknown: %1)").arg((int)(last));
                 }
                 m_worker->GUI(lst) << (m_worker->CONSOLE(lst) << (m_worker->ISMAS(lst) << UPDATE_STEP::UPDATE_FAILED));
             }