[sonic-utilities] Update submodule (#4963)

* src/sonic-utilities 9715244...a23479e (7):
  > [sonic-installer] Hyphens instead of underscores in command and subcommands (#983)
  >  Fix the None Type Exception when Interface Table does not exist (cold boot) as part of db migration (#986)
  > Support to verify reboot for secure boot (#979)
  > [filter-fdb] Fix For Vlan Defined With No CIDR (#976)
  > Intf table migration for APP_DB entries during warmboot (#980)
  > Enable HW watchdog before fast-reboot (#977)
  > [Multi NPU] Time Improvements to the config reload/load_minigraph commands  (#917)

Author: jleveque