fixup end of scenario saves
Merge pull request #174 from cbeck88/fixup_end_of_scenario_saves

fixup end of scenario saves

iceiceice writes: does anyone know why we have this line?
https://github.com/wesnoth/wesnoth/blob/master/src/play_controller.cpp#L752
it causes end of scenario saves to be stripped of all units
my theory is that it was for some point in time before carryover was implemented properly
i propose to remove it in 1.12 and master

AI0867 writes: See commit aa2cf7d.
Looks like the carryover refactoring might have made it do the opposite of what it used to.