Revert "Resolve problem with rendering thumbsup emoji"

ee/lib/ee/banzai/pipeline/gfm_pipeline.rb

@@ -24,8 +24,7 @@ module EE
 
           def filters
             [
-              *super,
-              ::Banzai::Filter::VulnerabilityReferenceFilter
+              *super
             ]
           end
         end

ee/spec/lib/banzai/filter/vulnerability_reference_filters_spec.rb

@@ -19,14 +19,6 @@ RSpec.describe Banzai::Filter::VulnerabilityReferenceFilter do
     reference_filter(reference, context)
   end
 
-  context '+1 emoji' do
-    let(:reference) { ":+1:" }
-
-    it 'does not link to a reference' do
-      expect(doc(reference).css('a')).to be_empty
-    end
-  end
-
   context 'internal reference' do
     let(:reference) { "+#{vulnerability.id}" }