Beautifier: Fix compilation

Error introduced with ca433d9b

.

Change-Id: I4b9604c20dd28b5b8843c0e476cd480d6191f904
Reviewed-by: David Schulz <david.schulz@digia.com>

src/plugins/beautifier/beautifierplugin.cpp

@@ -55,6 +55,7 @@
 #include <QAction>
 #include <QDir>
 #include <QFileInfo>
+#include <QDir>
 #include <QPlainTextEdit>
 #include <QProcess>
 #include <QScrollBar>