remove Canvas specific code from LinkedIn

fixes: CNVS-12505

test plan:
regression test linked in functionality

Change-Id: I7d4c327eefb8ac976c1d51e36aa6514c1742f739
Reviewed-on: https://gerrit.instructure.com/33458
Reviewed-by: Simon Williams <simon@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>
QA-Review: Trevor deHaan <tdehaan@instructure.com>
Product-Review: Jason Madsen <jmadsen@instructure.com>