Addresses https://github.com/AzureAD/microsoft-authentication-library-for-python/pull/358/files#r629667644

Author: rayluo

msal/region.py

@@ -1,5 +1,4 @@
 import os
-import json
 import logging
 
 logger = logging.getLogger(__name__)
@@ -17,7 +16,17 @@ def _detect_region_of_azure_function():
 
 
 def _detect_region_of_azure_vm(http_client):
-    url = "http://169.254.169.254/metadata/instance?api-version=2021-01-01"
+    url = (
+        "http://169.254.169.254/metadata/instance"
+
+        # Utilize the "route parameters" feature to obtain region as a string
+        # https://docs.microsoft.com/en-us/azure/virtual-machines/windows/instance-metadata-service?tabs=linux#route-parameters
+        "/compute/location?format=text"
+
+        # Location info is available since API version 2017-04-02
+        # https://docs.microsoft.com/en-us/azure/virtual-machines/windows/instance-metadata-service?tabs=linux#response-1
+        "&api-version=2021-01-01"
+        )
     logger.info(
         "Connecting to IMDS {}. "
         "You may want to use a shorter timeout on your http_client".format(url))
@@ -29,5 +38,5 @@ def _detect_region_of_azure_vm(http_client):
             "IMDS {} unavailable. Perhaps not running in Azure VM?".format(url))
         return None
     else:
-        return json.loads(resp.text)["compute"]["location"]
+        return resp.text.strip()