XOP-261: Revert.

XOP-261: Reinstate the server on 127.0.0.1 when no management
    interface is defined

    XOP-261/CA-96936: Remove Xapi_mgmt_iface.rebind
    Since the management interface is listening in IPv6 automatically if
    available.

    XAPI-261/CA-96936: Make himn_only more general
    To also manage the case of a localhost server.

    XOP-261/CA-96936: Prevent multiple starts of localhost server

    XOP-261/CA-96936: Issue a warning in case of multiple starts of HIMN server

Reverted since it broke TC-16120.

Signed-off-by: Jerome Maloberti <jerome.maloberti@citrix.com>