chore: make keycloak init script more robust

do not fail if the secret is not set, as is the case
for public clients. It seems that in current version of Keycloak
the server doesn't return a secret for public clients (makes sense)
but in older versions it did (doesn't make sense).

scripts/init-realm/init-realm.py

@@ -67,7 +67,8 @@ def _check_and_create_client(keycloak_admin, new_client):
         # We have to separately query the secret as it is not part of
         # the original respone
         secret = keycloak_admin.get_client_secrets(realm_client["id"])
-        realm_client["secret"] = secret["value"]
+        # public clients don't have secrets so default to None
+        realm_client["secret"] = secret.get("value", None)
 
         # We have to remove the auto-generated IDs of the protocol mapper(s)
         # before comparing to the to-be-created client.