mt reload causes error when adding refinery recipe

[ThePwnd]

Steps to reproduce:

1. Launch a Minecraft instance on 1.7.10 with MineTweaker3 v1.7.10-3.0.10, BuildCraft v7.1.23 or 7.1.24, and BuildCraft Compat v7.1.7 or 7.1.8
2. Create a new ZenScript file and add a new refinery recipe with the Refinery.addRecipe() method
3. Run /mt reload from in-game, verify the recipe has been registered
4. Run /mt reload from in-game again.

On step 4, you'll be greeted by an error in chat that says "An error occurred while processing this command." Checking the game log, you might notice this error being thrown:

[19:41:46] [Server thread/ERROR]: Couldn't process command: 'mt reload'
java.lang.NullPointerException
at buildcraft.compat.minetweaker.Refinery$AddRecipeAction.undo(Refinery.java:100) ~[Refinery$AddRecipeAction.class:?]
at minetweaker.runtime.MTTweaker.rollback(MTTweaker.java:88) ~[MTTweaker.class:?]
at minetweaker.MineTweakerImplementationAPI.reload(MineTweakerImplementationAPI.java:621) ~[MineTweakerImplementationAPI.class:?]
at minetweaker.MineTweakerImplementationAPI$1.execute(MineTweakerImplementationAPI.java:83) ~[MineTweakerImplementationAPI$1.class:?]
at minetweaker.MineTweakerImplementationAPI$19.execute(MineTweakerImplementationAPI.java:642) ~[MineTweakerImplementationAPI$19.class:?]
at minetweaker.mc1710.server.MCServer$MCCommand.func_71515_b(MCServer.java:124) ~[MCServer$MCCommand.class:?]
at net.minecraft.command.CommandHandler.func_71556_a(CommandHandler.java:94) [z.class:?]
at net.minecraft.network.NetHandlerPlayServer.func_147361_d(NetHandlerPlayServer.java:739) [nh.class:?]
at net.minecraft.network.NetHandlerPlayServer.func_147354_a(NetHandlerPlayServer.java:718) [nh.class:?]
at net.minecraft.network.play.client.C01PacketChatMessage.func_148833_a(SourceFile:37) [ir.class:?]
at net.minecraft.network.play.client.C01PacketChatMessage.func_148833_a(SourceFile:9) [ir.class:?]
at net.minecraft.network.NetworkManager.func_74428_b(NetworkManager.java:212) [ej.class:?]
at net.minecraft.network.NetworkSystem.func_151269_c(NetworkSystem.java:165) [nc.class:?]
at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:659) [MinecraftServer.class:?]
at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:547) [MinecraftServer.class:?]
at net.minecraft.server.integrated.IntegratedServer.func_71217_p(IntegratedServer.java:186) [bsx.class:?]
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:396) [MinecraftServer.class:?]
at net.minecraft.server.MinecraftServer$2.run(MinecraftServer.java:685) [?:?]