move sound keys cause "apply: Creating pipe: Too many open files" after re-enabling

[wombatzus]

After enabling, disabling, and re-enabling selectric-mode, keys on selectric-affected-bindings-list cause Emacs to hang briefly and then emit an ugly sound and the "apply: Creating pipe: Too many open files" error message. It appears that when re-enabling, the key binding being saved off is the selectric-mode-map binding, which causes a ton of backed up sounds to trigger. Looks like all that needs to be done is to undefine the keys in selectric-mode-map when exiting the mode.