调整leaseInfo为nil时的心跳参数处理逻辑与eureka server一致

[MI-cool]

Please provide issue(s) of this PR:
Fixes #1006

To help us figure out who should review this PR, please put an X in all the areas that this PR affects.

• ApiServer

Please check any characteristics that apply to this pull request.

• Does not have any user-facing changes. This may include API changes, behavior changes, performance improvements, etc.

[polaris-test-bot]

2023-03-15 18:25:21: =========TEST START==========
2023-03-15 18:25:47: Pre-Merge check success! Now we will perform a full automated test which is expected to take 2 hours, thank you for your patience.

[codecov]

Codecov Report

Merging #1007 (6fe29e7) into main (a0420f6) will increase coverage by 0.02%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main    #1007      +/-   ##
==========================================
+ Coverage   57.17%   57.19%   +0.02%     
==========================================
  Files         190      190              
  Lines       34388    34388              
==========================================
+ Hits        19660    19669       +9     
+ Misses      12162    12152      -10     
- Partials     2566     2567       +1     

see 6 files with indirect coverage changes

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more

[andrewshan]

LGTM