PathChooser: Update tooltip after change of base directory

Change-Id: I744ede2c6e011d1b7914b4e2922179fd5c366a69
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>

src/libs/utils/pathchooser.cpp

@@ -289,7 +289,10 @@ QString PathChooser::baseDirectory() const
 
 void PathChooser::setBaseDirectory(const QString &directory)
 {
+    if (d->m_baseDirectory == directory)
+        return;
     d->m_baseDirectory = directory;
+    d->m_lineEdit->triggerChanged();
 }
 
 FileName PathChooser::baseFileName() const