fixed unused variables in Z3_Context
fixed unused variables in Z3_Context

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