CID 1457825: stub version of nt_service_parse_options() makes coverity think we have dead code
```
*** CID 1457825: Possible Control flow issues (DEADCODE)
/src/app/main/main.c: 1244 in tor_run_main()
1238 memcpy(argv + tor_cfg->argc, tor_cfg->argv_owned,
1239 tor_cfg->argc_owned*sizeof(char*));
1240
1241 int done = 0;
1242 result = nt_service_parse_options(argc, argv, &done);
1243 if (done)
>>> CID 1457825: Possible Control flow issues (DEADCODE)
>>> Execution cannot reach this statement: "goto done;".
1244 goto done;
1245
1246 pubsub_install();
1247
1248 {
1249 int init_rv = tor_init(argc, argv);
```
issue