spec: fix lti variable expander spec

Change-Id: Iee1b920551a4698a9555e5800704462c7f6e11c6
Reviewed-on: https://gerrit.instructure.com/61714
Tested-by: Jenkins
Product-Review: Jacob Fugal <jacob@instructure.com>
QA-Review: Jacob Fugal <jacob@instructure.com>
Reviewed-by: James Williams  <jamesw@instructure.com>

spec/lib/lti/variable_expander_spec.rb

@@ -203,7 +203,7 @@ module Lti
       it 'has substitution for $Canvas.shard.id' do
         exp_hash = {test: '$Canvas.shard.id'}
         subject.expand_variables!(exp_hash)
-        expect(exp_hash[:test]).to eq 1
+        expect(exp_hash[:test]).to eq Shard.current.id
       end
 
       context 'context is a course' do