fix TLS reload doesn't work after delete cert file (#609)

[ti-srebot]

cherry-pick #609 to release-3.3
You can switch your code base to this Pull Request by using git-extras:

# In client-java repo:
git pr https://github.com/tikv/client-java/pull/612

After apply modifications, you can push your change to this PR via:

git push git@github.com:ti-srebot/client-java.git pr/612:release-3.3-75f05863389d

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Signed-off-by: Daemonxiao 735462752@qq.com

What problem does this PR solve?

TiSpark met some problem when use TLS Reload.

Problem Description: tryReload() is used as a task in ScheduledFuture. When tryReload() throws an exception, the schedule will be suppressed which makes tryReload() will not work.

What is changed and how does it work?

Add try-catch in tryReload().

    // If any execution of the task encounters an exception, subsequent executions are suppressed.
    private void tryReload() {
      // Add exception handling to avoid schedule stop.
      try {
        if (needReload()) {
          onChange.run();
        }
      } catch (Exception e) {
        logger.error("Failed to reload cert!" + e);
      }
    }

Code changes

• Has exported function/method change

Check List for Tests

This PR has been tested by at least one of the following methods:

• Unit test
• Integration test

Side effects

• NO side effects

Related changes

• Need to cherry-pick to the release branch

[ti-srebot]

/run-all-tests

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (release-3.3@aacbb8c). Click here to learn what that means.
The diff coverage is n/a.

@@              Coverage Diff               @@
##             release-3.3     #612   +/-   ##
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  Coverage               ?   34.63%           
  Complexity             ?     1418           
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  Files                  ?      278           
  Lines                  ?    17352           
  Branches               ?     1971           
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  Hits                   ?     6010           
  Misses                 ?    10737           
  Partials               ?      605           

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[iosmanthus]

LGTM