Fixed problem that adv_follow_path() lost unit's activity target.

See bug #22345


git-svn-id: svn://svn.gna.org/svn/freeciv/trunk@25682 a0f10bec-cc02-0410-94fc-a9cfff90b4cd
Make AI settler to consider base defense bonus when picking city spot.

Reported by Jacob Nevins <jtn>
Patch by Emmet Hikory <persia> and me

See gna bug #22079

git-svn-id: svn://svn.gna.org/svn/freeciv/trunk@25685 a0f10bec-cc02-0410-94fc-a9cfff90b4cd