resolvconf needs _at_RESTARTCMD_at_ to be replaced after r303062

Hi,

openresolv 3.8.1 added RESTARTCMD=_at_RESTARTCMD_at_ in
contrib/openresolv/resolvconf.in.
It is not replaced by the sed expressions in sbin/resolvconf/Makefile.

Error seen is "eval: _at_RESTARTCMD_at_: not found".

Current _at_RESTARTCMD \(.*\)_at_ sed expression needs to be kept for
pdns_recursor.in and a new expression added to replace _at_RESTARTCMD_at_.

The following worked for me:
RESTARTCMD_=    "/usr/sbin/service \\$$1 onestatus >/dev/null 2>\&1
\&\& /usr/sbin/service \\$$1 restart"

sed ... \
  ... \
  -e 's:_at_RESTARTCMD_at_:${RESTARTCMD_}:g' \
  ...

Regards,
Guy