Update partner-twilio-mobile-services-how-to-use-voice-sms.md

I get a 'page bot available' when browsing https://pingme.scm.azure-mobile.net/DebugConsole/Index.html, but a success when browsing https://pingme.scm.azure-mobile.net/DebugConsole
Merge pull request #1847 from trsneed/patch-1

Update partner-twilio-mobile-services-how-to-use-voice-sms.md