FancyLineEdit: Validate after setting validation function

Change-Id: I070c3de08dcdce7abc219a8e17d0ea1a531b2167
Reviewed-by: Eike Ziller <eike.ziller@theqtcompany.com>

src/libs/utils/fancylineedit.cpp

@@ -412,6 +412,7 @@ void FancyLineEdit::setOkColor(const QColor &c)
 void FancyLineEdit::setValidationFunction(const FancyLineEdit::ValidationFunction &fn)
 {
     d->m_validationFunction = fn;
+    validate();
 }
 
 FancyLineEdit::ValidationFunction FancyLineEdit::defaultValidationFunction()