bump ruby-saml-mod version

fixes CNVS-12871

test plan:

* regression test on saml logins
* the saml login redirect should not contain newlines encoded in the
  base64 (%0A characters)

Change-Id: I28470ce165ec1f8a90cfb22983d49d017bb72b80
Reviewed-on: https://gerrit.instructure.com/34311
Reviewed-by: Rob Orton <rob@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>
QA-Review: August Thornton <august@instructure.com>
Product-Review: Brian Palmer <brianp@instructure.com>