Merge pull request #712 from AzureAD/enable-ROPC-via-broker

Enable public client ROPC via broker

Author: fengga

msal/application.py

@@ -1714,7 +1714,7 @@ def acquire_token_by_username_password(
         """
         claims = _merge_claims_challenge_and_capabilities(
                 self._client_capabilities, claims_challenge)
-        if False:  # Disabled, for now. It was if self._enable_broker:
+        if self._enable_broker:
             from .broker import _signin_silently
             response = _signin_silently(
                 "https://{}/{}".format(self.authority.instance, self.authority.tenant),