Mirror image + EVENT_PLAYER_UNIT_SUMMON

[DracoL1ch]

Mirror image calls false-positive triggering of EVENT_PLAYER_UNIT_SUMMON event.
Repro:

• Create a trigger which will register EVENT_PLAYER_UNIT_SUMMON event, add
• displaying GetSummoningUnit() and GetSummonedUnit() names within trigger's action/condition.
• Use Mirror image spell ingame.

Expected:
"Blademaster has summoned Blademaster" per every illusion

Result:
"Blademaster has summoned " once (there are no GetSummonedUnit, it returns null just for one instance). Every illusion altough triggers it as well just right.

On the screen displayed names & handle ids