Add include

Change-Id: I160273e0029e90f692fcedb0227ccf67c9efbea3
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>

src/plugins/qbsprojectmanager/qbsprojectmanager.h

@@ -40,6 +40,7 @@ class Preferences;
 } // namespace qbs
 
 #include <QString>
+#include <QVariantMap>
 
 namespace ProjectExplorer {
 class Kit;