Fix nuxeo-filter element to filter user membership for Document Actions operation

This bug may have been introduced by ELEMENTS-558 (2.2.3 in HF03)

Step to reproduce:

1. In Designer > UI > Actions, add a new Operation with the following configuration
   • Name: myOperation
   • Available: enabled
   • Slot: Document Actions
   • Order: 1
   • icon: icons:question-answer
   • label: My Operation
2. In Nuxeo, add a user to the group nuxeo_grp
3. Log in with this user
4. Check that the operation is visible in Document Actions slot
5. In Designer, update the operation to add
   • Membership of: nuxeo_grp
6. Reload Nuxeo with this change

=> The operation is not visible any more whereas the user belongs to the group nuxeo_grp

Code from the operation

<nuxeo-slot-content name="myOperation" slot="DOCUMENT_ACTIONS" order="1" >
  <template>
    <nuxeo-filter group="nuxeo_grp" user="[[user]]">
      <template>
        <nuxeo-operation-button icon="icons:question-answer" label="My Operation"></nuxeo-operation-button>
      </template>
    </nuxeo-filter>
  </template>
</nuxeo-slot-content>