Revert "Install the windows service as "NT AUTHORITY\NetworkService""

This reverts commit 17db0a658f.

On Windows, switching to user `NT AUTHORITY\NetworkService` apparently
breaks logging (reported by @Aland_123).

dnscrypt-proxy/main.go

@@ -36,9 +36,6 @@ func main() {
 		Description:      "Encrypted/authenticated DNS proxy",
 		WorkingDirectory: pwd,
 	}
-	if serviceUserName := serviceStartupUserName(); serviceUserName != nil {
-		svcConfig.UserName = *serviceUserName
-	}
 	svcFlag := flag.String("service", "", fmt.Sprintf("Control the system service: %q", service.ControlAction))
 	app := &App{}
 	svc, err := service.New(app, svcConfig)

dnscrypt-proxy/privilege_linux.go

@@ -12,10 +12,6 @@ import (
 	"github.com/jedisct1/dlog"
 )
 
-func serviceStartupUserName() *string {
-	return nil
-}
-
 func (proxy *Proxy) dropPrivilege(userStr string, fds []*os.File) {
 	currentUser, err := user.Current()
 	if err != nil && currentUser.Uid != "0" {

dnscrypt-proxy/privilege_others.go

@@ -14,10 +14,6 @@ import (
 	"github.com/jedisct1/dlog"
 )
 
-func serviceStartupUserName() *string {
-	return nil
-}
-
 func (proxy *Proxy) dropPrivilege(userStr string, fds []*os.File) {
 	currentUser, err := user.Current()
 	if err != nil && currentUser.Uid != "0" {

dnscrypt-proxy/privilege_windows.go

@@ -2,9 +2,4 @@ package main
 
 import "os"
 
-func serviceStartupUserName() *string {
-	userName := "NT AUTHORITY\\NetworkService"
-	return &userName
-}
-
 func (proxy *Proxy) dropPrivilege(userStr string, fds []*os.File) {}