include missing header

Author: matthias-kleiner

Detectors/TPC/calibration/src/CorrectionMapsLoader.cxx

@@ -20,6 +20,7 @@
 #include "Framework/InitContext.h"
 #include "Framework/DeviceSpec.h"
 #include "DataFormatsCTP/LumiInfo.h"
+#include "TTree.h"
 
 using namespace o2::tpc;
 using namespace o2::framework;