In game this is an E-2D, but the ID of the aircraft in the game data is
E-2C. Presumably it was repainted at some point in a DCS update.
This adds a variant but doesn't delete the old one to avoid breaking
campaigns and factions. I moved blufor modern to the E-2D but the rest
of the factions are too old so we'll let them pretend.
Fixes https://github.com/dcs-liberation/dcs_liberation/issues/1696
(cherry picked from commit 33f00fb811a5f272cd2b65e1c5332e6a94d01c36)
c1f194b3d5
