Apply offroad terrain particle based on offroad check rather then boostpower

this should prevent issues with boostpower related scripts spawning errornous offroad dust

src/k_terrain.c

@@ -1064,7 +1064,8 @@ offroadhandle:
 	}
 
 	// - Being affected by offroad
-	if (mo->player->boostpower >= FRACUNIT)
+	// Using acutal offroad check here to prevent lua boostpower modifications from spawning the offroad particles - Nep
+	if (!(K_ApplyOffroad(mo->player) && mo->player->offroad > 0))
 	{
 		return;
 	}