fix: run metrics storage after bootstraping queues

[diafour]

Overview

RunMetrics starts go routines that access the TaskQueueSet info thus data race appears at start.

==================
WARNING: DATA RACE
Read at 0x00c00026fbc0 by goroutine 50:
  github.com/flant/shell-operator/pkg/task/queue.(*TaskQueueSet).Iterate()
  github.com/flant/shell-operator/pkg/shell-operator.(*ShellOperator).RunMetrics.func2()

Previous write at 0x00c00026fbc0 by main goroutine:
  runtime.mapassign_faststr()
      /usr/local/Cellar/go/1.17.2/libexec/src/runtime/map_faststr.go:202 +0x0
  github.com/flant/shell-operator/pkg/task/queue.(*TaskQueueSet).NewNamedQueue()
...

Goroutine 50 (running) created at:
  github.com/flant/shell-operator/pkg/shell-operator.(*ShellOperator).RunMetrics()
...