all: use parallel dialer for connecting upstream/api

So we don't have to depend on network stack probing to decide whether
ipv4 or ipv6 will be used.

While at it, also prevent a race report when doing the same parallel
resolving for os resolver, even though this race is harmless.

cmd/ctrld/cli.go

@@ -78,7 +78,7 @@ var rootCmd = &cobra.Command{
 }
 
 func curVersion() string {
-	if version != "dev" {
+	if version != "dev" && !strings.HasPrefix(version, "v") {
 		version = "v" + version
 	}
 	if len(commit) > 7 {