Revert "Workaround backspace issue for now"

This reverts commit ebfcd35ace.
Qt 4.5 commit b51dd5a7b328291c5dbda540ce228e7d867662cb eliminates the
need for this workaround for now.

src/plugins/texteditor/basetexteditor.cpp

@@ -1034,10 +1034,7 @@ bool BaseTextEditor::event(QEvent *e)
     d->m_contentsChanged = false;
     switch (e->type()) {
     case QEvent::ShortcutOverride:
-        if (static_cast<QKeyEvent*>(e)->key() == Qt::Key_Backspace)
-            e->accept();
-        else
-            e->ignore(); // we are a really nice citizen
+        e->ignore(); // we are a really nice citizen
         return true;
     default:
         break;