libnm: refine the condition for setting routing rule from/to property
Summary
libnm: remove validation on routing rule from/to prefix length 0
Purpose
When constructing the routing rule from D-Bus, the condition to set
from/to setting should be consistent as
nm_ip_routing_rule_from_string
(the function called when specifying
the routing rule through nmcli). Therefore, during the validation on
routing rule from/to setting, we should expect the same validation
result regardless of specifying the routing rule through libnm or
nmcli.
Checklist
Please read https://gitlab.freedesktop.org/NetworkManager/NetworkManager/-/blob/main/CONTRIBUTING.md before opening the merge request. In particular, check that:
-
the subject for all commits is concise and explicative -
the message for all commits explains the reason for the change -
the source is properly formatted -
any relevant documentation is up to date -
you have added unit tests if applicable