plugin register (#3321)

These plugins where missed in #3287 because their setup is done in a file
other than setup.go

Signed-off-by: Miek Gieben <miek@miek.nl>

plugin/root/root.go

@@ -12,12 +12,7 @@ import (
 
 var log = clog.NewWithPlugin("root")
 
-func init() {
-	caddy.RegisterPlugin("root", caddy.Plugin{
-		ServerType: "dns",
-		Action:     setup,
-	})
-}
+func init() { plugin.Register("root", setup) }
 
 func setup(c *caddy.Controller) error {
 	config := dnsserver.GetConfig(c)