Fix unit test breakage

Author: Jimmy John

src/onelogin/saml2/authn_request.py

@@ -89,7 +89,7 @@ def __init__(self, settings, force_authn=False, is_passive=False):
                 requested_authn_context_str += '    </samlp:RequestedAuthnContext>'
 
         attr_consuming_service_str = ''
-        if 'attributeConsumingService' in sp_data:
+        if 'attributeConsumingService' in sp_data and sp_data['attributeConsumingService']:
             # TODO: Do we have to account for the case when we have multiple attributeconsumers?
             # like will the index be > 1?
             attr_consuming_service_str = 'AttributeConsumingServiceIndex="1"'