message: also remove .so extension libs during clean_old_install
diff: @@ -35,7 +35,7 @@ if [ -d "/usr/local/include/eosio" ]; then
  libbuiltins)
  pushd lib &> /dev/null
  for lib in ${libraries[@]}; do
  - rm ${lib}.a ${lib}.dylib &> /dev/null
  + rm ${lib}.a ${lib}.dylib ${lib}.so &> /dev/null
  done
  popd &> /dev/null
  