[hotfix][doc] Override env.flink_branch for 2.0-preview1

This is a rc branch, but we should ensure that the url for this version doesn't contain rc suffix. Otherwise, all link will be broken.

.github/workflows/docs.yml

@@ -42,7 +42,10 @@ jobs:
  run: |
  currentBranch=$(git branch --show-current)
 
- echo "flink_branch=${currentBranch}" >> ${GITHUB_ENV}
+ if [ "${currentBranch}" = "release-2.0-preview1-rc1" ]; then
+ echo "flink_branch=release-2.0-preview1" >> ${GITHUB_ENV}
+ else
+ echo "flink_branch=${currentBranch}" >> ${GITHUB_ENV}
 
  if [ "${currentBranch}" = "master" ]; then
  echo "flink_alias=release-2.0" >> ${GITHUB_ENV}