[gssapi/gssproxy] 64e4a9: Eliminate some leftover dead code

[Robbie Harwood]

  Branch: refs/heads/main
  Home:   https://github.com/gssapi/gssproxy
  Commit: 64e4a99d0bfc28e20a7fd0b239d4bec138be77ff
      https://github.com/gssapi/gssproxy/commit/64e4a99d0bfc28e20a7fd0b239d4bec...
  Author: Robbie Harwood <rharwood(a)redhat.com&gt;
  Date:   2020-09-25 (Fri, 25 Sep 2020)

  Changed paths:
    M src/client/gpm_common.c
    M src/gp_rpc_indicate_mechs.c

  Log Message:
  -----------
  Eliminate some leftover dead code

Signed-off-by: Robbie Harwood <rharwood(a)redhat.com&gt;