FS-6287 --resolve When a broken registrar sends a 401 unauth then replies with a…

FS-6287 --resolve When a broken registrar sends a 401 unauth then replies with a subsequent 401 unauth without the stale=true attribute, sofia tries to invalidate the auth handle and get stuck in a state where it cannot recover until the reg handle is destroyed.  In this case, the provider in question has a bug on thier end when the nonce count rolls from nc=000000ff to nc=00000100 they start sending several consecitive 401 rather than a 401 with stale=true or a 403.  This change will allow it to reset properly and try again with nc=00000001 on the next try.

libs/sofia-sip/libsofia-sip-ua/nua/nua_client.c

@@ -1197,13 +1197,9 @@ int nua_base_client_check_restart(nua_client_request_t *cr,
 
       cr->cr_challenged = 1;
 
-      if (invalid) {
-	/* Bad username/password */
-	SU_DEBUG_7(("nua(%p): bad credentials, clearing them\n", (void *)nh));
-	auc_clear_credentials(&nh->nh_auth, NULL, NULL);
-      }
-      else if (auc_has_authorization(&nh->nh_auth))
-	return nua_client_restart(cr, 100, "Request Authorized by Cache");
+      if (!invalid && auc_has_authorization(&nh->nh_auth)) {
+		  return nua_client_restart(cr, 100, "Request Authorized by Cache");
+	  }
 
       orq = cr->cr_orq, cr->cr_orq = NULL;
 
@@ -1213,7 +1209,7 @@ int nua_base_client_check_restart(nua_client_request_t *cr,
       cr->cr_status = 0, cr->cr_phrase = NULL;
       nua_client_request_unref(cr);
 
-      return 1;
+      return 0;
     }
   }
   /* GriGiu : RFC-3261 status supported Retry-After */