Handle email address not exist. (#19089)

Author: KN4CK3R

routers/web/auth/auth.go

@@ -195,7 +195,7 @@ func SignInPost(ctx *context.Context) {
 	form := web.GetForm(ctx).(*forms.SignInForm)
 	u, source, err := auth_service.UserSignIn(form.UserName, form.Password)
 	if err != nil {
-		if user_model.IsErrUserNotExist(err) {
+		if user_model.IsErrUserNotExist(err) || user_model.IsErrEmailAddressNotExist(err) {
 			ctx.RenderWithErr(ctx.Tr("form.username_password_incorrect"), tplSignIn, &form)
 			log.Info("Failed authentication attempt for %s from %s: %v", form.UserName, ctx.RemoteAddr(), err)
 		} else if user_model.IsErrEmailAlreadyUsed(err) {