Fix a bug to show the wrong link status when the telephone cable is disconnected

Change the link status from "establishing" to "no_signal"

src/dsl_fapi.c

@@ -678,7 +678,7 @@ DLL_PUBLIC enum fapi_dsl_status fapi_dsl_line_get(struct fapi_dsl_ctx *ctx, stru
 
 		default:
 			strlcpy(obj->status, "Down", sizeof(obj->status));
-			strlcpy(obj->link_status, "EstablishingLink", sizeof(obj->link_status));
+			strlcpy(obj->link_status, "NoSignal", sizeof(obj->link_status));
 			break;
 		}
 	}