quoting 'man ovs-vswitchd.conf.db':
"The name must be alphanumeric and must not contain forward or backward
slashes."
OVS actually accepts a wider range of chars (all printable UTF-8 chars),
NetworkManager restricts this to ASCII char as it's a safer option for
now since OVS is not well documented on this matter.
https://bugzilla.redhat.com/show_bug.cgi?id=1788432
Fixes: e7d72a14f6 ('libnm-core: use different ifname validation function for OVS bridges, ports and interfaces')
(cherry picked from commit ed5a647ad1)