Show actual username as receiver name when sending email confirmation

endpoint/user/endpoint.go

@@ -493,7 +493,7 @@ func sendRegistrationVerification(tokenFactory otp.TokenFactory, templatemail *s
 	}
 
 	// Send email
-	if err = templatemail.Send(mail.Address{Name: "username", Address: email}, struct {
+	if err = templatemail.Send(mail.Address{Name: username, Address: email}, struct {
 		Username string
 		Token    string
 	}{