fix: add crossbeam-epoch dependency to fix panic backtrace messages on 0.7.1 version

[johanneshahn]

is it only branch 2.17 relevant or 3.0.0 too, maybe?

[EricShimizuKarbstein]

It is only relevant for 2.17 branch. The 3.0.0 branch doesn't show any symptoms of the problem.

The symptoms are that because of the panic, when it happens, some ports are not opened by the v2 server