(PR#10567) pubserver crash: ai-controlled unit has no goto destination

<URL: http://rt.freeciv.org/Ticket/Display.html?id=10567 >

> [per - Mon Oct 18 13:11:04 2004]:
> 
> Here is a patch to turn the assert into a freelog (hopefully).

I committed the patch.  It is clearly an improvement.  However I don't
think it will solve the original problem.  You've changed an assert into
a check-and-return but it wasn't this assert that was failing (see the
original bt).

jason