Revert "ZMPVelocityReferencedQPDebug.cpp not needed anymore"

This reverts commit ce351c3f.

src/CMakeLists.txt

@@ -52,6 +52,7 @@ SET(SOURCES
   ZMPRefTrajectoryGeneration/ZMPQPWithConstraint.cpp
   ZMPRefTrajectoryGeneration/ZMPConstrainedQPFastFormulation.cpp
   ZMPRefTrajectoryGeneration/ZMPVelocityReferencedQP.cpp
+  ZMPRefTrajectoryGeneration/ZMPVelocityReferencedQPDebug.cpp
   ZMPRefTrajectoryGeneration/OrientationsPreview.cpp
   ZMPRefTrajectoryGeneration/AnalyticalMorisawaAbstract.cpp
   ZMPRefTrajectoryGeneration/AnalyticalMorisawaCompact.cpp