ZdcConditions: Fix clang warning.

Unused private data member.

ForwardDetectors/ZDC/ZdcConditions/ZdcConditions/ZdcCablingService.h

@@ -74,7 +74,6 @@ public:
     int         m_channel_db[4][64];
     int         m_hv_db[4][64];
     int         m_ppm_db[16];
-    int         m_crate_db[8];
     int         m_crate_index[4];
     int         m_ncrate;
     //int         m_crate_lookup[2][3][2];