chore(syncthing): try just mounting one

apps/syncthing/overlays/media/deployment-patch.yaml

@@ -7,10 +7,10 @@ spec:
     containers:
       - name: syncthing
         volumeMounts:
-          - name: sync-keys
-            mountPath: /var/syncthing/config/cert.pem
-            subPath: cert.pem
-            readOnly: true
+          # - name: sync-keys
+          #   mountPath: /var/syncthing/config/cert.pem
+          #   subPath: cert.pem
+          #   readOnly: true
           - name: sync-keys
             mountPath: /var/syncthing/config/key.pem
             readOnly: true
@@ -19,6 +19,3 @@ spec:
       - name: sync-keys
         secret:
           secretName: sync-secret
-          items:
-            - key: cert.pem
-            - key: key.pem