Merge branch 'couchdb-3284'

closes #223
diff --git a/src/couch_query_servers.erl b/src/couch_query_servers.erl
index ea7628e..92d9e24 100644
--- a/src/couch_query_servers.erl
+++ b/src/couch_query_servers.erl
@@ -289,6 +289,8 @@
             throw({forbidden, Message});
         {[{<<"unauthorized">>, Message}]} ->
             throw({unauthorized, Message});
+        {[{_, Message}]} ->
+            throw({unknown_error, Message});
         Message when is_binary(Message) ->
             throw({unknown_error, Message})
     end.