[dovecot/core] fdf3e1: configure: hardening logic is backwards

[GitHub]

  Branch: refs/heads/master
  Home:   https://github.com/dovecot/core
  Commit: fdf3e1e28e824a562b895c8c6b5d77d70146d357
      https://github.com/dovecot/core/commit/fdf3e1e28e824a562b895c8c6b5d77d70146d357
  Author: Josef 'Jeff' Sipek <jeff.sipek at dovecot.fi>
  Date:   2016-09-12 (Mon, 12 Sep 2016)

  Changed paths:
    M configure.ac
    M m4/cc_fortify.m4
    M m4/cc_pie.m4
    M m4/cc_stack_protector.m4
    M m4/ld_relro.m4

  Log Message:
  -----------
  configure: hardening logic is backwards

Before this change, the argument parsing was busted.  The --help string only
compounded the incorrect behavior by suggesting that --disable-hardening
could take a yes/no argument.
                                 | before   | after
  ------------------------------+----------+--------
  <no option>                   | enable   | enable
  --enable-hardening            | disable  | enable
  --enable-hardening=yes        | disable  | enable
  --enable-hardening=no         | enable   | disable
  --disable-hardening           | enable   | disable
  --disable-hardening=yes       | error    | error
  --disable-hardening=no        | error    | error