[submodule] Update submodule dhcprelay to the latest HEAD automatically (#24622)

#### Why I did it
src/dhcprelay
```
* 39e28c4 - (HEAD -> master, origin/master, origin/HEAD) [dhcp4relay]: Fix swss-common references (#81) (25 hours ago) [Shivashankar C R]
```
#### How I did it
#### How to verify it
#### Description for the changelog

Author: mssonicbld