fixes for login providers using dependency injection pattern

Author: samnotsowise

src/Authentication/LoginProviderBasedAuthenticationProviders/LoginProviderCredentialsAuthenticationProvider.php

@@ -25,6 +25,6 @@ class LoginProviderCredentialsAuthenticationProvider extends ModelLoginProviderA
 {
     protected function getLoginProviderClassName()
     {
-        return LoginProvider::getDefaultLoginProviderClassName();
+        return LoginProvider::class;
     }
-}
+}

src/Authentication/LoginProviderBasedAuthenticationProviders/LoginProviderTokenAuthenticationProvider.php

@@ -26,7 +26,7 @@ class LoginProviderTokenAuthenticationProvider extends TokenAuthenticationProvid
 {
     protected function logUserIn(Model $user)
     {
-        $loginProvider = LoginProvider::getDefaultLoginProvider();
+        $loginProvider = LoginProvider::getProvider();
         $loginProvider->forceLogin($user);
     }
 }