fakevim: fix 'Delete' in insert mode to delete exactly one char again

Reviewed-by: Kornelia Poenitz

src/plugins/fakevim/fakevimhandler.cpp

@@ -2730,6 +2730,7 @@ EventResult FakeVimHandler::Private::handleInsertMode(const Input &input)
         }
         endEditBlock();
     } else if (input.isKey(Key_Delete)) {
+        setAnchor();
         cursor().deleteChar();
         m_lastInsertion.clear();
     } else if (input.isKey(Key_PageDown) || input.isControl('f')) {