Update to commonmarker 0.23.4

Merge branch 'security-update-cmark-gfm-14-7' into '14-7-stable-ee'

See merge request gitlab-org/security/gitlab!2283

Changelog: security

Gemfile

@@ -153,7 +153,7 @@ gem 'html-pipeline', '~> 2.13.2'
 gem 'deckar01-task_list', '2.3.1'
 gem 'gitlab-markup', '~> 1.8.0'
 gem 'github-markup', '~> 1.7.0', require: 'github/markup'
-gem 'commonmarker', '~> 0.23.2'
+gem 'commonmarker', '~> 0.23.4'
 gem 'kramdown', '~> 2.3.1'
 gem 'RedCloth', '~> 4.3.2'
 gem 'rdoc', '~> 6.3.2'

Gemfile.lock

@@ -200,7 +200,7 @@ GEM
       open4 (~> 1.3)
     coderay (1.1.3)
     colored2 (3.1.2)
-    commonmarker (0.23.2)
+    commonmarker (0.23.4)
     concurrent-ruby (1.1.9)
     connection_pool (2.2.2)
     contracts (0.11.0)
@@ -1421,7 +1421,7 @@ DEPENDENCIES
   capybara-screenshot (~> 1.0.22)
   carrierwave (~> 1.3)
   charlock_holmes (~> 0.7.7)
-  commonmarker (~> 0.23.2)
+  commonmarker (~> 0.23.4)
   concurrent-ruby (~> 1.1)
   connection_pool (~> 2.0)
   countries (~> 3.0)