[module/bp] fix: Unavailable RIB service prevents listing account balance
Example of unavailable service:
Result in boobank
boobank> list
Account Balance Coming
------------------------------------------+----------+----------
2020-07-18 00:12:31,395:DEBUG:bcall:2.0:bcall.py:92:backend_process <Backend 'bp'>: Calling function iter_resources
[...]
2020-07-18 00:12:32,700:DEBUG:backend.bp.browser:2.0:browsers.py:720:internal_callback Handle https://voscomptesenligne.labanquepostale.fr/voscomptes/canalXHTML/comptesCommun/imprimerRIB/init-imprimer_rib.ea?numeroCompte=[REDACTED] with AccountRIB
> [REDACTED]/.local/share/weboob/modules/2.0/bp/pages/accountlist.py(422)get_iban()
-> m = re.search(self.iban_regexp, extract_text(self.data))
(Pdb) p extract_text(self.data)
None
(Pdb) c
2020-07-18 00:12:41,867:WARNING:backend.bp.browser.accountlist.item_account:2.0:elements.py:384:handle_attr Attribute iban (in [REDACTED]/.local/share/weboob/modules/2.0/bp/pages/accountlist.py:217) raises TypeError('expected string or bytes-like object')
2020-07-18 00:12:41,868:DEBUG:bcall:2.0:bcall.py:98:backend_process <Backend 'bp'>: Called function iter_resources raised an error: TypeError('expected string or bytes-like object')
Bug(bp): expected string or bytes-like object