if this flag is set, diff and diff will not include properties that are set to their default value.
This is the opposite of NM_SETTING_COMPARE_FLAG_DIFF_RESULT_WITH_DEFAULT. If both flags are set together,
NM_SETTING_COMPARE_FLAG_DIFF_RESULT_WITH_DEFAULT wins. If both flags are unset, this means to exclude default properties if there
is a setting to compare, but include all properties, if the setting 'b' is missing. This is the legacy behaviour of libnm-util, where
diff behaved differently depending on whether the setting 'b' was available. If
NM_SETTING_COMPARE_FLAG_DIFF_RESULT_WITH_DEFAULT is set, diff will also set the
flags NM_SETTING_DIFF_RESULT_IN_A_DEFAULT and NM_SETTING_DIFF_RESULT_IN_B_DEFAULT, if the values are default
values.