log error reports in the root_domain_accounts shard

fixes: CNVS-15074

Wraps the log_exception method in a shard.activate for the
domain_root_account.  This is required because the method gets called
after the LoadAccount middleware has been called.

Test Case:
  - Create an error on one shard, such as going to localhost:3000/42 to
    raise a 404.
  - Open the shards error reports and the error should be in the list.
  - Open the default account and the error should not be in the list.

Note:

Need to add the following to config/environments/development.rb.
Without this the error won't be logged.  Rails3 will not call the log
method in the middleware.

  config.consider_all_requests_local = false

Change-Id: I2b8c3fd3fc714ab75cf3b872e6546ffd651e6882
Reviewed-on: https://gerrit.instructure.com/40610
Reviewed-by: Cody Cutrer <cody@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>
QA-Review: August Thornton <august@instructure.com>
Product-Review: Nick Cloward <ncloward@instructure.com>