When weboob update command fails, modules are deleted

EDIT: Main idea of this ticket is https://framagit.org/bnjbvr/kresus/issues/662#note_142005.

This happens on current stable version (0.11.1)

What I observed :

• The update command failed
• The locale modules were deleted
• When fetching accounts through Reports > Sync I get :

 File "./weboob/main.py", line 271, in <module>
    content = Connector(bankuuid, params).fetch(command)
  File "./weboob/main.py", line 114, in __init__
    self.backend = self.weboob.build_backend(modulename, parameters)
  File "/usr/local/lib/python2.7/dist-packages/weboob-1.3-py2.7.egg/weboob/core/ouiboube.py", line 419, in build_backend
    raise ModuleLoadError(module_name, 'Module does not exist.')
weboob.exceptions.ModuleLoadError: Module does not exist.

[2017-09-30 16:28:50:322] info - sources/weboob | Command left with non-zero code.
[2017-09-30 16:28:50:327] error - helpers | when fetching operations: Weboob failure: Traceback (most recent call last):
  File "./weboob/main.py", line 271, in <module>
    content = Connector(bankuuid, params).fetch(command)
  File "./weboob/main.py", line 114, in __init__
    self.backend = self.weboob.build_backend(modulename, parameters)
  File "/usr/local/lib/python2.7/dist-packages/weboob-1.3-py2.7.egg/weboob/core/ouiboube.py", line 419, in build_backend
    raise ModuleLoadError(module_name, 'Module does not exist.')
weboob.exceptions.ModuleLoadError: Module does not exist.

As the interface with weboob changed a lot on devel branch, this might not happen anymore. But all installation are broken. A quick fix would be necessary, like reinstalling the modules on catching ModuleLoadError.