Fix the import for RequestBodyModel

This apparently got moved in develop, so cherry-picking the merge
stuff.

This should be reverted once we merge develop again

synapse/rest/client/reporting.py

@@ -32,8 +32,8 @@ from synapse.http.servlet import (
     parse_json_object_from_request,
 )
 from synapse.http.site import SynapseRequest
+from synapse.rest.models import RequestBodyModel
 from synapse.types import JsonDict
-from synapse.types.rest import RequestBodyModel
 
 from ._base import client_patterns