Disable allow failure tag for markdown

.gitlab-industrial-ci-kinetic-no-rosinstall.yml

@@ -111,7 +111,6 @@ bash_syntax:
 markdown_syntax:
   stage: postcheck
   script: docker run -v ${PWD}:/ac cytopia/awesome-ci syntax-markdown --path=/ac --extension=md --ignore=.ci_config --custom="-r ~MD013"
-  allow_failure: yes
   when: always
   tags:
     - docker

.gitlab-industrial-ci-kinetic-with-rosinstall.yml

@@ -113,7 +113,6 @@ bash_syntax:
 markdown_syntax:
   stage: postcheck
   script: docker run -v ${PWD}:/ac cytopia/awesome-ci syntax-markdown --path=/ac --extension=md --ignore=.ci_config --custom="-r ~MD013"
-  allow_failure: yes
   when: always
   tags:
     - docker