Fast MAI: bug fix for scenarios when there is no enemy leader (for the AI)

In this case, it can happen that there are no goals (e.g. if there are
also no villages or if the AI has no leader). Previously, this
situation caused an error message.

data/ai/micro_ais/cas/ca_fast_move.lua

@@ -131,6 +131,7 @@ function ca_fast_move:execution(ai, cfg, self)
     end
 
     local keep_moving, next_goal = true, 0
+    if (not goals[1]) then keep_moving = false end
     while keep_moving do
         keep_moving = false