WIP Fix compilation with cppgsl 3.1.0
Fixes a compilation error affecting lhcb-lcg-dev4 and lhcb-lcg-dev3 slots. @graven thanks for the hint.
WIP because it needs cppgsl 3.1.0, incompatible with 3.0.1 found in LCG_97a
Edited by Marco Cattaneo
Fixes a compilation error affecting lhcb-lcg-dev4 and lhcb-lcg-dev3 slots. @graven thanks for the hint.
WIP because it needs cppgsl 3.1.0, incompatible with 3.0.1 found in LCG_97a