Reset single Child Bridge Pair Code

**Describe The Bug:**
I have a Plugin that i am using to create Child Bridge. Each Child Bridge "Username" generated uniquely by third party Controller and push to Config JSON using Homebridge UI API.

I am facing problem when if i disable Paired Child bridge and Enable it gain from the Bridge Setting page. the "Username" gets generated automatically. this leads to a New Bridge that i have setup in my home app. to Avoid this i replace the Newly generated "Username "(Mac) with Previously set username and after restarting the bridge the child bridge shows paired on the Bridge settings tab of Plugin. I have removed the Hub from the home app manually but i can figure out a way to reset the paring of this particular  Child bridge without changing the "Username"(Mac).

**Environment:**

* **Node.js Version**: 14.17.0
* **NPM Version**: 6.14.13
* **Homebridge Version**: 1.3.4
* **Operating System**: Raspbian 
* **Process Supervisor**: Systemd 


