Only define variables if branch name matches pattern

Author: paoloredis

.github/workflows/autocomment_jira_link.yaml

@@ -22,12 +22,6 @@ jobs:
           REPO: ${{ github.repository }}
           BRANCH_NAME: ${{ github.event.pull_request.head.ref }}
         run: |
-          CREATE_COMMENT_URL="https://api.github.com/repos/${REPO}/issues/${PR_NUMBER}/comments"
-          
-          JIRA_TICKET=$(grep -Eo '^DOC-[0-9]+' <<< "$BRANCH_NAME")
-          JIRA_LINK="https://redislabs.atlassian.net/browse/${JIRA_TICKET}"
-          COMMENT="[${JIRA_TICKET}](${JIRA_LINK})"
-          
           generate_post_data()
           {
             cat <<EOF
@@ -37,6 +31,12 @@ jobs:
           }
 
           if [[ "$BRANCH_NAME" == DOC-* ]]; then
+            CREATE_COMMENT_URL="https://api.github.com/repos/${REPO}/issues/${PR_NUMBER}/comments"
+
+            JIRA_TICKET=$(grep -Eo '^DOC-[0-9]+' <<< "$BRANCH_NAME")
+            JIRA_LINK="https://redislabs.atlassian.net/browse/${JIRA_TICKET}"
+            COMMENT="[${JIRA_TICKET}](${JIRA_LINK})"
+
             # Write comment on pull request
             curl -Ls \
               -X POST \