TextEditor: Clear suggestion on Focus Out Event

Change-Id: I6fa3d5218a48985ca6590d454f494466d1d79927
Reviewed-by: Marcus Tillmanns <marcus.tillmanns@qt.io>
Reviewed-by: David Schulz <david.schulz@qt.io>

src/plugins/texteditor/texteditor.cpp

@@ -8325,6 +8325,7 @@ void TextEditorWidget::focusOutEvent(QFocusEvent *e)
         viewport()->update(d->cursorUpdateRect(d->m_cursors));
     }
     d->updateHighlights();
+    d->clearCurrentSuggestion();
 }
 
 void TextEditorWidgetPrivate::maybeSelectLine()