comparisons/uralkal: PGSSLMODE=disable

comparisons-api-v2 builds its postgres URI without sslmode, so both lib/pq
(migrations) and pgx (api) default to requiring TLS, which the uralkal
postgres does not serve.

apps/comparisons/uralkal/backend.yaml

@@ -63,6 +63,10 @@ spec:
             value:
               _default: "postgres"
 
+          - name: PGSSLMODE
+            value:
+              _default: "disable"
+
           - name: HTTP_PORT
             value:
               _default: "8080"