Tweak the Spartan "Agoge" tech, affect champions only.
The agoge did not concern perioikoi, thus should not affect the citizen soldiers.
Spartan hoplites are supposed to be the strongest infantry in the game, this makes them again more effective than Macedonian Silver Shields.
Patch by: borg-
Accepted by: Nescio
Differential Revision: https://code.wildfiregames.com/D2846