Fix crash when search yields no results

[LostLuma]

Resolves #20 for Minecraft 1.7 and above.
This is the same as #21 except applied in the least invasive way to the vanilla class that was used here.

[SpaceWalkerRS]

I'm not too fond of including a beta version of Mixin Extras in the mod. I'd like to wait for it to enter a new release and merge this once Loader updates to it. Then again it doesn't strike me as a very obscure crash so perhaps a more invasive fix in the meantime is the way to go.

[LostLuma]

Alright, I was kinda wondering whether it'd be a bad idea :) I shall change it to make the value of n be 0 instead.