fix c-tagging in 1dimension

A bug in the c-tagging implementation was reported by the H_c FCNC team. They are using C-tagging in 1 dimension (no 2D tagging) and the new c-tagging code was not supporting this option. Now it has been fixed and tested locally by me on the VH legacy code and by the analysis team.

A new property has been added:

 declareProperty( "useCTagging",                        m_useCTag=false,       "Enabled only for FixedCut or Continuous WPs: define wether the cuts refer to b-tagging or c-tagging");

it applies only to 1D tagging.

@aivina