CORD-1990 Handle exceptions where e.message is another exception

Change-Id: I989ed94074604f32b16ae2d65e1903d217e1e816
diff --git a/xos/synchronizers/new_base/event_loop.py b/xos/synchronizers/new_base/event_loop.py
index 68398a4..bff74e3 100644
--- a/xos/synchronizers/new_base/event_loop.py
+++ b/xos/synchronizers/new_base/event_loop.py
@@ -234,7 +234,7 @@
         current_code = o.backend_code
 
         if hasattr(e, 'message'):
-            status = e.message
+            status = str(e.message)
         else:
             status = str(e)