MC-22950: Enable 2FA by default for Admins

- Fixed typo causing providers to not be selected

Author: nathanjosiah

TwoFactorAuth/Controller/Adminhtml/Tfa/Configurepost.php

@@ -120,7 +120,7 @@ public function execute()
         if ($this->validate($selected)) {
             $this->configResource->saveConfig(
                 TfaInterface::XML_PATH_FORCED_PROVIDERS,
-                implode(', ',array_keys($selected))
+                implode(',', array_keys($selected))
             );
             $this->config->reinit();
             $this->getMessageManager()->addSuccessMessage(