fix discovered config default values

[ilyam8]

Summary

Job charts created from discovered (local listeners) configs have priority 0 because default configuration settings are not applied. This PR fixes it.

Test Plan

Before

DBG jobmgr/manager.go:293 creating ntpd[local] job, config: map[__provider__:sd:net_listeners __source__:discoverer=net_listeners,host=localhost,file=/opt/netdata/usr/lib/netdata/conf.d/go.d/sd/net_listeners.conf __source_type__:discovered address:127.0.0.1:123 collect_peers:false module:ntpd name:local] component="job manager"

After

DBG jobmgr/manager.go:293 creating ntpd[local] job, config: map[__provider__:sd:net_listeners __source__:discoverer=net_listeners,host=localhost,file=/opt/netdata/usr/lib/netdata/conf.d/go.d/sd/net_listeners.conf __source_type__:discovered address:127.0.0.1:123 autodetection_retry:0 collect_peers:false module:ntpd name:local priority:70000 update_every:1] component="job manager

Additional Information

For users: How does this change affect me?