add slash to SS_SERVICE constant

src/include/66/constants.h

src/lib66/graph/graph_build_service.c

src/lib66/resolve/resolve_check_g.c

src/lib66/resolve/resolve_read_g.c

src/lib66/resolve/resolve_remove_g.c

src/lib66/resolve/resolve_write_g.c

src/lib66/sanitize/sanitize_system.c

src/lib66/service/service_resolve_write.c

src/lib66/state/state_check.c

src/lib66/state/state_read.c

src/lib66/state/state_rmfile.c

src/lib66/state/state_write.c

src/lib66/utils/name_isvalid.c