Better redirect for single external auth provider.

src/Squidex/Areas/IdentityServer/Controllers/Account/AccountController.cs

@@ -198,6 +198,17 @@ namespace Squidex.Areas.IdentityServer.Controllers.Account
 
             var externalProviders = await signInManager.GetExternalProvidersAsync();
 
+            if (externalProviders.Count == 1 && !allowPasswordAuth)
+            {
+                var provider = externalProviders[0].AuthenticationScheme;
+
+                var properties =
+                    signInManager.ConfigureExternalAuthenticationProperties(provider,
+                        Url.Action(nameof(ExternalCallback), new { ReturnUrl = returnUrl }));
+
+                return Challenge(properties, provider);
+            }
+
             var vm = new LoginVM
             {
                 ExternalProviders = externalProviders,
@@ -242,7 +253,7 @@ namespace Squidex.Areas.IdentityServer.Controllers.Account
 
             var isLoggedIn = result.Succeeded;
 
-            UserWithClaims user = null;
+            UserWithClaims user;
 
             if (isLoggedIn)
             {

src/Squidex/Areas/IdentityServer/Views/Account/Login.cshtml

@@ -87,15 +87,4 @@ else
     <p class="profile-footer">
         Already registered? <a asp-controller="Account" asp-action="Login" asp-route-returnurl="@Model.ReturnUrl">Click here to login</a>
     </p>
-}
-
-@if (!Model.HasPasswordAuth && Model.ExternalProviders.Count == 1)
-{
-    <script>
-        var redirectButtons = document.getElementsByClassName("redirect-button");
-
-        if (redirectButtons.length === 1) {
-            redirectButtons[0].click();
-        }
-    </script>
 }