Fix matrix_synapse_oidc_providers parsing

roles/custom/matrix-synapse/templates/synapse/homeserver.yaml.j2

@@ -2116,8 +2116,7 @@ saml2_config:
   #  attribute_requirements:
   #    - attribute: userGroup
   #      value: "synapseUsers"
-oidc_providers:
-  {{ matrix_synapse_oidc_providers|to_nice_yaml(indent=2, width=999999) }}
+oidc_providers: {{ matrix_synapse_oidc_providers }}
 {% endif %}