Test-SRVRecord returns a large number of false positive errors for PDC SRV record

[cjpalmer]

I have been running the monitor in my environment for a while now (with the modifications that I have in my pull request). On problem that I haven't addressed yet is that Test-SRVRecord returns an inordinately large number of false positive records for the PDC SRV record (saying it is missing). The record is not missing and I am unable to make it fail when I am testing. My thought is similar to my solution for the External DNS test with ping. If there is a failed result, just test again and it will likely come back successfully. I haven't had time to test this or try to implement it but I wanted to raise the issue in case anyone else has a better idea.