Fix a few broken things

- Fixed some broken KEShove tests
- Fixed fuel tank material not showing up the first time you view it in the menu
- Probably fixed #392

lua/entities/acf_engine/init.lua

@@ -126,7 +126,8 @@ local TickInterval = engine.TickInterval
 local function GetPitchVolume(Engine)
 	local RPM = Engine.FlyRPM
 	local Pitch = Clamp(20 + (RPM * Engine.SoundPitch) * 0.02, 1, 255)
-	local Throttle = Engine.RevLimited and 0 or Engine.Throttle
+	-- Rev limiter code disabled because it has issues with the volume delta time, but it's still here if we need it
+	local Throttle = --[[Engine.RevLimited and 0 or]] Engine.Throttle
 	local Volume = 0.25 + (0.1 + 0.9 * ((RPM / Engine.LimitRPM) ^ 1.5)) * Throttle * 0.666
 
 	return Pitch, Volume * Engine.SoundVolume

lua/tests/acf/damage/damage_sv/acf_keshove.lua

@@ -17,7 +17,8 @@ return {
             GetPhysicsObject = function()
                 return {
                     IsValid = function() return true end,
-                    ApplyForceOffset = State.applyForceStub
+                    ApplyForceOffset = State.applyForceStub,
+                    GetMass = function() return 1 end,
                 }
             end,
             GetChildren = function() return {} end,

lua/vgui/acf_panel.lua

@@ -609,7 +609,7 @@ function PANEL:AddModelPreview(Model, Rotate)
 		if not Center then
 			if ModelData.IsOnStandby(Path) then
 				ModelData.QueueRefresh(Path, self, function()
-					self:UpdateModel(Path)
+					self:UpdateModel(Path, Material)
 				end)
 			end