revalidate when the expected kind changes

otherwise the initial value set before the kind was set will be
displayed as validated by the default kind's rules.

src/libs/utils/pathchooser.cpp

@@ -490,7 +490,10 @@ QString PathChooser::homePath()
 
 void PathChooser::setExpectedKind(Kind expected)
 {
+    if (m_d->m_acceptingKind == expected)
+        return;
     m_d->m_acceptingKind = expected;
+    m_d->m_lineEdit->triggerChanged();
 }
 
 PathChooser::Kind PathChooser::expectedKind() const