rlm_sqlippool segfaults on wrong/missing rlm_sql instance

[Alan DeKok]

Stephan Jaeger wrote in July:
> rlm_sqlippool segfaults if you specify a non existing sql module
> instance.
> 
> I modified it a bit to behave like rlm_sqlhpwippool, it now throws an
> error if the specified module instance does not exist:

  Fixed, thanks.

  (Yes, my inbox is many months deep).

  Alan DeKok.