version.txt: remove empty line

Screws up the formatting in from places
Fred: bug fix for checking for trappable units at the map edge

ai_helper.find_opposite_hex_adjacent() returns nil if the opposite hex
is on the map border, which needs to be taken into account here.
Fred attack exec: bug fix for units moving out of the way blocking other attack hexes

In an attack combination, a unit moving out of the way of a unit might
then block a hex for another unit later in the same combination.  If it
cannot move out of the way for that latter unit any more, the move
combination needs to be abandoned.