remotecontrol: required version for MacOSX is 10.8

Change-Id: I11b64b79de90d776fd117aa687c971ed80172b76
Reviewed-on: https://gerrit.libreoffice.org/12245
Reviewed-by: Tor Lillqvist <tml@collabora.com>
Tested-by: Tor Lillqvist <tml@collabora.com>