[REF][runbot] Add validation of module duplicate

Currently if there is a duplicate module in all repositories show a error and stop process of copy:
```python
Traceback (most recent call last):
  File "../odoo/odoo/openerp/http.py", line 476, in _handle_exception
    return super(JsonRequest, self)._handle_exception(exception)
  File "../odoo/odoo/openerp/http.py", line 495, in dispatch
    result = self._call_function(**self.params)
  File "../odoo/odoo/openerp/http.py", line 311, in _call_function
    return checked_call(self.db, *args, **kwargs)
  File "../odoo/odoo/openerp/service/model.py", line 113, in wrapper
    return f(dbname, *args, **kwargs)
  File "../odoo/odoo/openerp/http.py", line 308, in checked_call
    return self.endpoint(*a, **kw)
  File "../odoo/odoo/openerp/http.py", line 685, in __call__
    return self.method(*args, **kw)
  File "../odoo/odoo/openerp/http.py", line 360, in response_wrap
    response = f(*args, **kw)
  File "../odoo/odoo/addons/web/controllers/main.py", line 987, in call_button
    action = self._call_kw(model, method, args, {})
  File "../odoo/odoo/addons/web/controllers/main.py", line 975, in _call_kw
    return getattr(request.registry.get(model), method)(request.cr, request.uid, *args, **kwargs)
  File "../odoo/odoo/openerp/api.py", line 204, in wrapper
    return old_api(self, *args, **kwargs)
  File "../odoo/community-addons/odoo-extra/runbot/runbot.py", line 371, in cron
    self.scheduler(cr, uid, ids)
  File "../odoo/odoo/openerp/api.py", line 204, in wrapper
    return old_api(self, *args, **kwargs)
  File "../odoo/community-addons/odoo-extra/runbot/runbot.py", line 318, in scheduler
    pending_build.schedule()
  File "../odoo/odoo/openerp/api.py", line 202, in wrapper
    return new_api(self, *args, **kwargs)
  File "../odoo/odoo/openerp/api.py", line 517, in new_api
    result = method(self._model, cr, uid, self.ids, *args, **kwargs)
  File "../odoo/community-addons/odoo-extra/runbot/runbot.py", line 867, in schedule
    cr.commit()
  File "../odoo/odoo/openerp/api.py", line 204, in wrapper
    return old_api(self, *args, **kwargs)
  File "../odoo/community-addons/odoo-extra/runbot/runbot.py", line 717, in job_10_test_base
    cmd, mods = build.cmd()
  File "../odoo/odoo/openerp/api.py", line 202, in wrapper
    return new_api(self, *args, **kwargs)
  File "../odoo/odoo/openerp/api.py", line 517, in new_api
    result = method(self._model, cr, uid, self.ids, *args, **kwargs)
  File "../odoo/community-addons/odoo-extra/runbot/runbot.py", line 600, in checkout
    pid_col = 'pid' if cr._cnx.server_version >= 90200 else 'procpid'
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/shutil.py", line 292, in move
    raise Error, "Destination path '%s' already exists" % real_dst
Error: Destination path '../odoo/community-addons/odoo-extra/runbot/static/build/01286-7-0-8afaf3/openerp/addons/account_bank_statement_extensions' already exists
```
Now, with this PR change error to a log message and continue with process.