event filters for ghost entities are incorrect

[jagoly]

in main.lua, the event filters are using
{ filter = "ghost", ghost_name = COMBINATOR_NAME } and { filter = "ghost", name = COMBINATOR_NAME }
for ghosts. These are both incorrect, "ghost" is a mode that just accepts EVERY ghost and doesn't take a name.

Rather, they should both be { filter = "ghost_name", name = COMBINATOR_NAME }.

Probably won't make any difference other than making event handling 0.000001% faster, but I noticed it in my own project that used cybersyn's event handling as a reference, so figured I'd put an issue here :)