Don't null unused fields as they default to null.

mods/d2k/rules/structures.yaml

@@ -838,7 +838,6 @@ high_tech_factory:
 		SquadSize: 3
 		LongDesc: Ornithopters hit the target with bombs
 		UnitType: ornithopter
-		SelectTargetSound:
 		DisplayBeacon: True
 		CameraActor: camera
 	WithProductionOverlay@WELDING:
@@ -953,9 +952,6 @@ palace:
 		LongDesc: Launches an atomic missile at a target location
 		BeginChargeSound: HI_PREP.AUD
 		EndChargeSound: HI_DHRDY.AUD
-		SelectTargetSound:
-		LaunchSound:
-		IncomingSound:
 		MissileWeapon: atomic
 		SpawnOffset: -512,1c171,0
 		DisplayBeacon: True

mods/ts/rules/gdi-structures.yaml

@@ -403,11 +403,8 @@ GAPLUG:
 		ChargeTime: 180
 		Description: Ion Cannon
 		LongDesc: Initiate an Ion Cannon strike.\nApplies instant damage to a small area.
-		BeginChargeSound:
 		EndChargeSound: 00-i156.aud
-		LaunchSound:
 		SelectTargetSound:
-		InsufficientPowerSound:
 		DisplayRadarPing: True
 		CameraActor: camera
 	ProduceActorPower:

mods/ts/rules/nod-support.yaml

@@ -238,10 +238,8 @@ NAMISL:
 		ChargeTime: 540
 		Description: Cluster Missile
 		LongDesc: Launches a conventional warhead\nat a target location.
-		BeginChargeSound:
 		EndChargeSound: 00-i154.aud
 		SelectTargetSound:
-		InsufficientPowerSound:
 		IncomingSound: 00-i150.aud
 		LaunchSound: icbm1.aud
 		MissileWeapon: ClusterMissile