The credential wait's test stays under a second, and a failed watch says the re-read, not a restart (issue 1496)

Review of 3baeaec: TestAwaitCredential took 1.9 s, over the unit limit; it now
sets the watch's settle to 10 ms, writes at 20 ms and gives up at 100 ms (0.2 s).
The watch's journal line for a failure named a bundle and a restart; the
credential wait now says it is read again every 30 s instead.

node-tools/cmd/node-tools/main.go

@@ -171,7 +171,8 @@ func awaitCredential(file string, until time.Time, say func(string, ...any)) (bu
 		case changed <- struct{}{}:
 		default:
 		}
-	}, func(format string, args ...any) { say(format, args...) })
+	}, func(format string, args ...any) { say(format, args...) },
+		fmt.Sprintf("the credential is read again every %s instead", rereadEvery))
 	if werr != nil {
 		say("cannot watch %s (%v): it is read again every %s instead", file, werr, rereadEvery)
 	} else {