Update TenantID comment

Updating the comment to specify it has to be used if using SPN

Author: IanB111

InvokeMasterScript.ps1

@@ -16,7 +16,7 @@ Set-ExecutionPolicy -ExecutionPolicy Unrestricted
     #Uncomment the below 2 lines if using a SPN Cert to gather data
     #-CertificateThumbprint "<Replace with the thumbprint of your cert used for SPN>" `
     #-ApplicationId "<Replace with the ClientID of the SPN>" `
-    #Uncomment the below line if using TenantID as part of sign in of the Management Endpoint
+    #Uncomment the below line if using TenantID as part of sign in of the Management Endpoint, requried if using SPN
     #-TenantId "<Replace with the TenantId for the AzureStack>"