Revert "cork: pass through gpg sockets"

[ajeddeloh]

This reverts commit 02e1f8c.

This should finish reverting all of the gpg bind mounting related changes.

[bgilbert]

It does not bring mantle to the state of 5ceb160, because that would also exclude #813, #810, #811, #809, #808, #807, #804, #783, #805, #796, #801, and #797.