force to use service/user directory for user frontend file

src/include/66/service.h

src/lib66/exec/ssexec_parse.c

src/lib66/module/parse_module.c

src/lib66/parse/parse_compute_list.c

src/lib66/parse/parse_frontend.c

src/lib66/parse/parse_interdependences.c

src/lib66/sanitize/sanitize_system.c

src/lib66/service/service_frontend_path.c