Count a machine that does not resolve and holds a place as on the network for its name and the mesh's sources too (issue 1833)

The tunnel kept such a machine while the names and the packet filter's sources from the mesh, read from their own
unchecked resolve, dropped it when that pass refused it too (a seat claimed twice): every other machine was sent the
hub as a peer without its name or its address. onTheNetwork keeps it by the same rule as network().

go/compose/network.go

@@ -242,7 +242,9 @@ func (c *composer) whereEveryoneIs() (map[string]string, error) {
 }
 
 // onTheNetwork is every placed machine that resolves the private network: has an address AND runs what puts it there
-// (novox/hq issue 079). A machine that does not resolve is not counted, and said.
+// (novox/hq issue 079). A machine that does not resolve keeps its place when it holds one (a key and an address), by the
+// same rule as network(), so its name and its address stay where the tunnel to it does (issue 1833); one without is not
+// counted, and said.
 func (c *composer) onTheNetwork() []Node {
 	var out []Node
 	for _, n := range c.in.sorted() {
@@ -256,6 +258,12 @@ func (c *composer) onTheNetwork() []Node {
 			catalogue.Node{Name: n.Name, Site: n.Place.Site, Capabilities: n.Capabilities},
 			catalogue.World{Unchecked: true, Holdings: c.in.Holdings})
 		if err != nil {
+			if n.Place.Key != "" {
+				c.say("%s could not be resolved and keeps its place on the private network at %s, so the others keep their path to it",
+					n.Name, n.Place.Address)
+				out = append(out, n)
+				continue
+			}
 			c.say("%s is not counted as on the network: it does not resolve: %v", n.Name, err)
 			continue
 		}