Change "security" contact type to "other"

* because SATOSA only accepts values from a certain enumeration

config/saml2-backend.yaml

@@ -36,7 +36,7 @@ config:
     organization: {display_name: TU Wien, name: TU Wien, url: 'https://www.tuwien.at/'}
     contact_person:
     - {contact_type: technical, email_address: 'tudata@tuwien.ac.at', given_name: Technical Support}
-    - {contact_type: security, email_address: 'tudata@tuwien.ac.at', given_name: Security Contact}
+    - {contact_type: other, email_address: 'tudata@tuwien.ac.at', given_name: Security Contact}
 
     metadata:
       remote: