Impacted versions:
11.0
Steps to reproduce:
Translations -> Synchronize Terms -> Language : Arabic
Current behavior:
Error:
Odoo Server Error
```
Error:
Traceback (most recent call last):
  File "/Users/rubyonrails/odoo/odoo/http.py", line 648, in _handle_exception
    return super(JsonRequest, self)._handle_exception(exception)
  File "/Users/rubyonrails/odoo/odoo/http.py", line 309, in _handle_exception
    raise pycompat.reraise(type(exception), exception, sys.exc_info()[2])
  File "/Users/rubyonrails/odoo/odoo/tools/pycompat.py", line 86, in reraise
    raise value
  File "/Users/rubyonrails/odoo/odoo/http.py", line 685, in dispatch
    result = self._call_function(**self.params)
  File "/Users/rubyonrails/odoo/odoo/http.py", line 341, in _call_function
    return checked_call(self.db, *args, **kwargs)
  File "/Users/rubyonrails/odoo/odoo/service/model.py", line 97, in wrapper
    return f(dbname, *args, **kwargs)
  File "/Users/rubyonrails/odoo/odoo/http.py", line 334, in checked_call
    result = self.endpoint(*a, **kw)
  File "/Users/rubyonrails/odoo/odoo/http.py", line 929, in __call__
    return self.method(*args, **kw)
  File "/Users/rubyonrails/odoo/odoo/http.py", line 514, in response_wrap
    response = f(*args, **kw)
  File "/Users/rubyonrails/odoo/addons/web/controllers/main.py", line 920, in call_button
    action = self._call_kw(model, method, args, {})
  File "/Users/rubyonrails/odoo/addons/web/controllers/main.py", line 908, in _call_kw
    return call_kw(request.env[model], method, args, kwargs)
  File "/Users/rubyonrails/odoo/odoo/api.py", line 689, in call_kw
    return call_kw_multi(method, model, args, kwargs)
  File "/Users/rubyonrails/odoo/odoo/api.py", line 680, in call_kw_multi
    result = method(recs, *args, **kwargs)
  File "/Users/rubyonrails/odoo/odoo/addons/base/module/wizard/base_update_translations.py", line 42, in act_update
    tools.trans_load_data(self._cr, buf, 'csv', this.lang, lang_name=lang_name)
  File "/Users/rubyonrails/odoo/odoo/tools/translate.py", line 1034, in trans_load_data
    fileobj.seek(0)
ValueError: I/O operation on closed file.
```
Expected behavior:
Do Synchronize Terms


odoo/addons/base/module/wizard/base_language_install.py
return self.env['res.lang'].get_available()
    lang = fields.Selection(_get_languages, string='Language', required=True)
    overwrite = fields.Boolean('Overwrite Existing Terms',
                               help="If you check this box, your customized translations will be overwritten and replaced by the official ones.")
    state = fields.Selection([('init', 'init'), ('done', 'done')],
                             string='Status', readonly=True, default='init')
    @api.multi
    def lang_install(self):
        self.ensure_one()
        mods = self.env['ir.module.module'].search([('state', '=', 'installed')])
        mods.with_context(overwrite=self.overwrite)._update_translations(self.lang)
        self.state = 'done'
        return {
            'name': _('Language Pack'),
            'view_type': 'form',
            'view_mode': 'form',
            'view_id': False,
            'res_model': 'base.language.install',
            'domain': [],
            'context': dict(self._context, active_ids=self.ids),
            'type': 'ir.actions.act_window',
            'target': 'new',
            'res_id': self.id,
        }
    def reload(self):
        return {
            'type': 'ir.actions.client',
            'tag': 'reload',
        }