Revert "Add initial support for  mixpanel instrumentation key"
Revert "Add initial support for  mixpanel instrumentation key"

This reverts commit 274473ce8269419b4c5ba6c696d8a328f6be8a71.

projectkudu/WebJobsPortal,projectkudu/AzureFunctions,chunye/azure-functions-ux,projectkudu/WebJobsPortal,chunye/azure-functions-ux,agruning/azure-functions-ux,chunye/azure-functions-ux,projectkudu/AzureFunctions,agruning/azure-functions-ux,agruning/azure-functions-ux,chunye/azure-functions-ux,chunye/azure-functions-ux,projectkudu/WebJobsPortal,agruning/azure-functions-ux,projectkudu/AzureFunctions,projectkudu/WebJobsPortal,projectkudu/AzureFunctions,agruning/azure-functions-ux