web admin: bulk import generate useless admin API audit log entry in DB

[nqb]

Each time you make a CSV import, two rows are inserted in admin_api_audit_log table:

• one with JSON payload
• one with an empty JSON payload (useless)

Example:

*************************** 62. row ***************************
        id: 62
 tenant_id: 1
created_at: 2020-01-09 09:17:09.413567
 user_name: admin
    action: api.v1.Users.bulk_import
 object_id: NULL
       url: /api/v1/users/bulk_import
    method: POST
   request: {"ignoreInsertIfNotExists":false,"ignoreUpdateIfExists":false,"items":[{"firstname":"firstname","lastname":"lastname","password":"************************","pid":"pid"},{"firstname":"Nicolas","lastname":"Quiniou","password":"************************","pid":"nqb"},{"firstname":"Test","lastname":"Quiniou","password":"************************","pid":"test"},{"firstname":"Test","lastname":"Quiniou","password":"************************","pid":"test3"}],"stopOnFirstError":true}
    status: 200
*************************** 63. row ***************************
        id: 63
 tenant_id: 1
created_at: 2020-01-09 09:17:09.473079
 user_name: admin
    action: api.v1.Users.bulk_import
 object_id: NULL
       url: /api/v1/users/bulk_import
    method: POST
   request: {"items":[]}
    status: 200

To Reproduce
Steps to reproduce the behavior:

1. Make a CSV import
2. Go in Admin API Audit logs menu

Expected behavior
Only one Admin API audit log entry by bulk import.

[nqb]

In fact, I just noticed that web admin send two API calls. Admin API audit log is correct, frontend needs to be adjusted. Reassigning.