core: set routing rule protocol properly
When creating NMPlatformRoutingRule from NMIPRouteRule object, the protocol is not being set properly. According to linux kernel documentation FRA_PROTOCOL indicates the originator of the rule.
In this case the route rule is coming from a connection and therefore the originator of the rule is the user. The correct value is RTPROT_STATIC which means the rule is installed by the administrator.
Fixes: 3f934774 ("core: add handling of IP routing rules to NMDevice")
Signed-off-by: Fernando Fernandez Mancera ffmancera@riseup.net