Remove useless bit of code from cheatsheet

[katomuso]

When the time comes to select var in cheatsheet, we first remove var lists with :url as the first element. However, there are no such var lists anymore.

This bit of code comes from the initial implementation, where lists with :url existed (though they served no purpose) and were later removed (bfdd79c28f27e1fab6f1cd2759606ff6f4d13899).

Since this code doesn't serve any purpose anymore, we can easily remove it. In fact, we can remove the entire cider-cheatsheet--select-var function and replace its call, as it feels redundant, if you think that would be appropriate.

[bbatsov]

Since this code doesn't serve any purpose anymore, we can easily remove it. In fact, we can remove the entire cider-cheatsheet--select-var function and replace its call, as it feels redundant, if you think that would be appropriate.

I guess you'll tweak the code further anyways, if you decide to re-order the selection logic. Thanks for giving the cheatsheet some love!