Temporarily disable VP digitization with DD4hep

When building with DD4hep the VP DE is different.

CMakeLists.txt

@@ -15,6 +15,11 @@ CMAKE_MINIMUM_REQUIRED(VERSION 2.8.5)
 find_package(GaudiProject)
 #---------------------------------------------------------------
 
+set(USE_DD4HEP "OFF" CACHE BOOL "Controls whether DD4hep is used for the subdetectors supporting it")
+if (USE_DD4HEP)
+  add_compile_definitions(USE_DD4HEP)
+endif()
+
 # Declare project name and version
 gaudi_project(Boole v41r3
               USE Lbcom v31r3

Digi/DigiAlg/src/BuildMCTrackInfo.h

@@ -17,7 +17,6 @@
 
 #include "Event/MCTrackInfo.h"
 
-class DeVP;
 class DeUTDetector;
 class DeFTDetector;
 

VP/VPDigitisation/src/VPDepositCreator.cpp

@@ -34,6 +34,8 @@
  *  @date   20/09/09
  */
 
+#ifndef USE_DD4HEP
+
 namespace VPDepositCreatorConditions {
   struct ConditionsCache {
     ConditionsCache( std::array<double, 52> diffCoeff, std::array<std::array<double, 4>, 52> dTP )
@@ -535,3 +537,5 @@ void VPDepositCreator::deadTimeSim( LHCb::MCVPDigits& digits, const DeVP& det, c
   m_numVPDeadtimeKilled += numKilled;
   return;
 }
+
+#endif