PHP README.md doc should not include XML sample showing AppID and secret for route service

[hgonzago]

This should have been removed from the original as we do not have the ability to register services as an item, rather an app.

Go to https://github.com/Esri/resource-proxy/tree/master/PHP

In the XML Example section > this specific part

  <serverUrl
      url="http://route.arcgis.com"
      matchAll="true"
      oauth2Endpoint="https://www.arcgis.com/sharing/oauth2"
      clientId="6Xo1x5L1tz7k9Kn2dc"
      clientSecret="5dca5d50d0e6fe422c867b6efcf969b6ca2"
      rateLimit="120"
      rateLimitPeriod="60">
  </serverUrl>

[hgonzago]

Closing after some more testing. As it looks both app and services work with appid and secret, as opposed to current doc that states only apps.