Fix to CISCO_ACCOUNTING_HACK

[Alan DeKok]

Pavel Levshin wrote:
> We had some random crashes while processing ~600 RPS of accounting with
> freeradius 2.1.7 and rlm_sql (MySQL).
> 
> Coredumps showed that crashes occurs mostly in MySQL library. MySQL
> handle was used twice by different threads. Problem is so simple that I
> wonder why it has not been catched long ago. Here comes a patch:

  Fixed, thanks.

> It looks like this bug has been fixed in ic-radius 0.17 at 2001.

  About when he stopped sending patches back to FreeRADIUS.  Oh well.

  Alan DeKok.