Bonding options are related and some combinations don't make sense. Basically,
MIIMON and ARP monitoring mode (and related options) are mutually exclusive.
When nmcli set arp_interval of "0" (the default value),
nm_setting_bond_add_option() cleared the MIIMON options (miimon, updelay and
downdelay).

This commit works around libnm-util's nm_setting_bond_add_option() that clears
miimon options when arp_interval is being set and vice versa, but doesn't
take into account the value of "0" that should be regarded as 'disable'.

https://bugzilla.redhat.com/show_bug.cgi?id=1007355