update webex

test plan:
  verify conference type is moved to plugin config and out of
  conferences

Change-Id: Ia483a5d4e1d605ac064e1361fef98ce80cb579d4
Reviewed-on: https://gerrit.instructure.com/32134
Reviewed-by: Jake Sorce <jake@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>
Product-Review: Adam Phillipps <adam@instructure.com>
QA-Review: Adam Phillipps <adam@instructure.com>