Fixes

• SAML: the lookup of the app (SocialApp) was working correctly for apps configured via the settings, but failed when the app was configured via the Django admin.
• Keycloak: fixed reversal of the callback URL, which was reversed using "openid_connect_callback" instead of "keycloak_callback". Although the resulting URL is the same, it results in a NoReverseMatch error when allauth.socialaccount.providers.openid_connect is not present in INSTALLED_APPS.