Update minimal reconnect period

[AlbumenJ]

What is the purpose of the change

Set minimal reconnect period as 60s even heartbeat is smaller than 60s

Brief changelog

Verifying this change

Checklist

• Make sure there is a GitHub_issue field for the change (usually before you start working on it). Trivial changes like typos do not require a GitHub issue. Your pull request should address just this issue, without pulling in other changes - one PR resolves one issue.
• Each commit in the pull request should have a meaningful subject line and body.
• Write a pull request description that is detailed enough to understand what the pull request does, how, and why.
• Check if is necessary to patch to Dubbo 3 if you are work on Dubbo 2.7
• Write necessary unit-test to verify your logic correction, more mock a little better when cross module dependency exist. If the new feature or significant change is committed, please remember to add sample in dubbo samples project.
• Add some description to dubbo-website project if you are requesting to add a feature.
• GitHub Actions works fine on your own branch.
• If this contribution is large, please follow the Software Donation Guide.

[sonarqubecloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

0.0% Coverage
0.0% Duplication

[codecov-commenter]

Codecov Report

Merging #12639 (0b6d205) into 3.2 (70a948a) will decrease coverage by 0.59%.
The diff coverage is n/a.

@@             Coverage Diff              @@
##                3.2   #12639      +/-   ##
============================================
- Coverage     69.93%   69.35%   -0.59%     
+ Complexity      315        2     -313     
============================================
  Files          1852     1629     -223     
  Lines         97719    67378   -30341     
  Branches      17847     9882    -7965     
============================================
- Hits          68343    46732   -21611     
+ Misses        23900    16128    -7772     
+ Partials       5476     4518     -958     

see 3481 files with indirect coverage changes

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[EarthChen]

LGTM