[FIX] Fix for validation error on invoices with l10n_es_account_invoice_...

...sequence

The module raises the error:

File "/opt/openerp/v7/spain/l10n_es_account_invoice_sequence/account_invoice.py", line 71, in action_number
    context=context)
TypeError: action_number() got an unexpected keyword argument 'context'

This fix worked for me.

More info: https://groups.google.com/forum/#!msg/openerp-spain-users/Znh1SS3HiTo/zVvQIhB9CCUJ