fix type error (probably due to typescript update)
> hap-nodejs@1.1.0 build
> rimraf dist && tsc && node .github/node-persist-ignore.js
src/lib/Accessory.ts:2142:34 - error TS2345: Argument of type 'string | undefined' is not assignable to parameter of type 'string'.
Type 'undefined' is not assignable to type 'string'.
2142 const version = net.isIP(entry); // check if ip address was specified or an interface name
~~~~~
Found 1 error in src/lib/Accessory.ts:2142
Process finished with exit code 2
fix type error (probably due to typescript update)