[FIX][report_xls] Protect import. (#64) about reporting-engine HOT 6 CLOSED

2016-08-23 12:37:09,675 19647 ERROR test openerp.service.report: Exception: type object 'report_xls' has no attribute 'xls_types'
Traceback (most recent call last):
  File "/home/anass/Documents/workspace/odoo/odoo8/openerp/service/report.py", line 93, in go
    result, format = openerp.report.render_report(cr, uid, ids, object, datas, context)
  File "/home/anass/Documents/workspace/odoo/odoo8/openerp/report/__init__.py", line 40, in render_report
    return registry['ir.actions.report.xml'].render_report(cr, uid, ids, name, data, context)
  File "/home/anass/Documents/workspace/odoo/odoo8/openerp/api.py", line 268, in wrapper
    return old_api(self, *args, **kwargs)
  File "/home/anass/Documents/workspace/odoo/odoo8/openerp/addons/base/ir/ir_actions.py", line 156, in render_report
    return new_report.create(cr, uid, res_ids, data, context)
  File "/home/anass/.local/share/Odoo/addons/8.0/report_xls/report_xls.py", line 118, in create
    return self.create_source_xls(cr, uid, ids, data, context)
  File "/home/anass/.local/share/Odoo/addons/8.0/report_xls/report_xls.py", line 148, in create_source_xls
    self.generate_xls_report(_p, _xs, data, objs, wb)
  File "/home/anass/.local/share/Odoo/addons/8.0/account_financial_report_webkit_xls/report/partner_ledger_xls.py", line 78, in generate_xls_report
    row_data = self.xls_row_template(c_specs, [x[0] for x in c_specs])
  File "/home/anass/.local/share/Odoo/addons/8.0/report_xls/report_xls.py", line 213, in xls_row_template
    'write_cell_func': report_xls.xls_types[c[3]]})
AttributeError: type object 'report_xls' has no attribute 'xls_types'

    xls_types = xls_types