In the engineConnExec.sh script, replace the absolute path of CLASSPA…

[sjgllgh]

What is the purpose of the change

In the engineConnExec.sh script, replace the absolute path in the CLASSPATH with a variable.

For example: Originally, it's set as
export CLASSPATH="${PWD}/conf:/app/linkis/conf:${PWD}/lib/:/app/linkis/lib/linkis-commons/public-module/",
where /app/linkis is controlled by linkismanager.

Modify it to:
export LINKIS_HOME="/app/linkis"
export CLASSPATH="${PWD}/conf:${LINKIS_HOME}/conf:${PWD}/lib/:${LINKIS_HOME}/lib/linkis-commons/public-module/"
Here, /app/linkis is controlled by engingconnmanager.

Related issues/PRs

Related issues: close #5275

Checklist

• I have read the Contributing Guidelines on pull requests.
• I have explained the need for this PR and the problem it solves
• I have explained the changes or the new features added to this PR
• [] I have added tests corresponding to this change
• [] I have updated the documentation to reflect this change
• I have verified that this change is backward compatible (If not, please discuss on the Linkis mailing list first)
• [] If this is a code change: I have written unit tests to fully verify the new behavior.