karma module exposes race condition

[lehmannro]

When the same item is modified in one single message and was not previously created the hard-coded replies utter invalid responses.

Query: racecondition-- racecondition++ racecondition==

Response: racecondition hat einen karmawert von 0

Response: racecondition hat nun einen karmawert von -1

Response: racecondition hat nun einen karmawert von 1

Or:

Query: karmabug++ karmabug--

Response: karmabug hat nun einen karmawert von 0

Failure: twisted.web.error.Error: 409 Conflict

[lehmannro]

Fixed in 767a5a50ff72f4a07782f1c11c325c183ceb58e0.