removed warning in backend/Z3_Context.hpp when building a zero-sized array
removed warning in backend/Z3_Context.hpp when building a zero-sized array

nbruns1/metaSMT,agra-uni-bremen/metaSMT,nbruns1/metaSMT,finnhaedicke/metaSMT,hoangmle/metaSMT,finnhaedicke/metaSMT,hoangmle/metaSMT,finnhaedicke/metaSMT,agra-uni-bremen/metaSMT,nbruns1/metaSMT,hoangmle/metaSMT,agra-uni-bremen/metaSMT