default thread_pool_watchdog == default cli_timeout

Avoid (potential) issues due to the monotonic clock not advancing for ~10
seconds such as for virtual machine snapshots or migrations.

In such a scenario, we would kill a child after cli_timeout anyway, so
using the same timeout by default for the watchdog also should reduce
the additional risk implied by it.

Ref	#2814

bin/varnishd/mgt/mgt_pool.c

@@ -156,7 +156,7 @@ struct parspec WRK_parspec[] = {
 		"If no queued work have been released for this long,"
 		" the worker process panics itself.",
 		EXPERIMENTAL,
-		"10", "seconds" },
+		"60", "seconds" },
 	{ "thread_pool_destroy_delay",
 		tweak_timeout, &mgt_param.wthread_destroy_delay,
 		"0.01", NULL,

include/tbl/params.h

@@ -1202,7 +1202,7 @@ PARAM(
 	/* typ */	timeout,
 	/* min */	"0.1",
 	/* max */	NULL,
-	/* default */	"10.000",
+	/* default */	"60.000",
 	/* units */	"seconds",
 	/* flags */	EXPERIMENTAL,
 	/* s-text */