remove planDesc parsing logic temporarily

[huaxiabuluo]

What type of PR is this?

• [ ] bug
• [ ] feature
• [ ] enhancement

What problem(s) does this PR solve?

Issue(s) number:

• vesoft-inc/nebula-studio-ent#532

Description:

• Must execute client.Ping() after Client instance initiation
• Due to breaking changes of protocol, temporarily remove the parsing logic for planDesc

How do you solve it?

Special notes for your reviewer, ex. impact of this fix, design document, etc: