Fix some typos in comments. (#4100)

Signed-off-by: Hu Shuai <hus.fnst@cn.fujitsu.com>

core/dnsserver/config.go

@@ -52,7 +52,7 @@ type Config struct {
 	registry map[string]plugin.Handler
 }
 
-// keyForConfig build a key for identifying the configs during setup time
+// keyForConfig builds a key for identifying the configs during setup time
 func keyForConfig(blocIndex int, blocKeyIndex int) string {
 	return fmt.Sprintf("%d:%d", blocIndex, blocKeyIndex)
 }

core/dnsserver/onstartup.go

@@ -2,7 +2,7 @@ package dnsserver
 
 import "fmt"
 
-// startUpZones create the text that we show when starting up:
+// startUpZones creates the text that we show when starting up:
 // grpc://example.com.:1055
 // example.com.:1053 on 127.0.0.1
 func startUpZones(protocol, addr string, zones map[string]*Config) string {

core/dnsserver/server.go

@@ -194,7 +194,7 @@ func (s *Server) Stop() (err error) {
 // Address together with Stop() implement caddy.GracefulServer.
 func (s *Server) Address() string { return s.Addr }
 
-// ServeDNS is the entry point for every request to the address that s
+// ServeDNS is the entry point for every request to the address that 
 // is bound to. It acts as a multiplexer for the requests zonename as
 // defined in the request so that the correct zone
 // (configuration and plugin stack) will handle the request.

core/dnsserver/server_grpc.go

@@ -34,7 +34,7 @@ func NewServergRPC(addr string, group []*Config) (*ServergRPC, error) {
 		return nil, err
 	}
 	// The *tls* plugin must make sure that multiple conflicting
-	// TLS configuration return an error: it can only be specified once.
+	// TLS configuration returns an error: it can only be specified once.
 	var tlsConfig *tls.Config
 	for _, conf := range s.zones {
 		// Should we error if some configs *don't* have TLS?

core/dnsserver/server_https.go

@@ -33,7 +33,7 @@ func NewServerHTTPS(addr string, group []*Config) (*ServerHTTPS, error) {
 		return nil, err
 	}
 	// The *tls* plugin must make sure that multiple conflicting
-	// TLS configuration return an error: it can only be specified once.
+	// TLS configuration returns an error: it can only be specified once.
 	var tlsConfig *tls.Config
 	for _, conf := range s.zones {
 		// Should we error if some configs *don't* have TLS?

core/dnsserver/server_tls.go

@@ -26,7 +26,7 @@ func NewServerTLS(addr string, group []*Config) (*ServerTLS, error) {
 		return nil, err
 	}
 	// The *tls* plugin must make sure that multiple conflicting
-	// TLS configuration return an error: it can only be specified once.
+	// TLS configuration returns an error: it can only be specified once.
 	var tlsConfig *tls.Config
 	for _, conf := range s.zones {
 		// Should we error if some configs *don't* have TLS?