Fix Aeon M4 bug with incorrect platoon reference

[maudlin27]

Fixes a bug caused by a reference to a string instead of a platoon

Error message given prior to this change:
WARNING: Error running lua script: ...alliance\maps\scca_coop_a04\scca_coop_a04_script.lua(891): Expected a game object. (Did you call with '.' instead of ':'?)
stack traceback:
[C]: in function `PlatoonExists'
...alliance\maps\scca_coop_a04\scca_coop_a04_script.lua(891): in function <...alliance\maps\scca_coop_a04\scca_coop_a04_script.lua:880>

[maudlin27]

Although this fixed the issue for the replay where it occured, running a fresh replay results in the error:
WARNING: Error running lua script: ...alliance\maps\scca_coop_a04\scca_coop_a04_script.lua(893): Game object has been destroyed
stack traceback:
[C]: in function `AssignUnitsToPlatoon'
...alliance\maps\scca_coop_a04\scca_coop_a04_script.lua(893): in function <...alliance\maps\scca_coop_a04\scca_coop_a04_script.lua:880>

I'll look into some more to see if the new error can be mitigated.

[maudlin27]

With thanks to relent0r, the second issue I encountered was where some of the transports in the platoon were dead - have updated the PR to fix this (by only transferring over living transports)