bugfix: only try to parse the TorVersion if there is one.

svn:r5697

src/or/config.c

@@ -3531,7 +3531,7 @@ or_state_validate(or_state_t *old_state, or_state_t *state)
     warn(LD_GENERAL, "Unable to parse entry nodes: %s", err);
     return -1;
   }
-  if (tor_version_parse(state->TorVersion, &v)) {
+  if (state->TorVersion && tor_version_parse(state->TorVersion, &v)) {
     warn(LD_GENERAL, "Can't parse Tor version '%s' from your state file. "
          "Proceeding anyway.", state->TorVersion);
   }