[Issue-11966][pulsar-proxy] set default http proxy request timeout

[zzzming]

Fixes #11966

Address missing http proxy request timeout in issue #11966

Motivation

Set http proxy request timeout in pulsar-proxy

Modifications

Set default http proxy request timeout in pulsar-proxy as 30 seconds

Verifying this change

This change is a trivial rework / code cleanup without any test coverage.

Does this pull request potentially affect one of the following parts:

If yes was chosen, please highlight the changes

• Dependencies (does it add or upgrade a dependency): (yes / no)
• The public API: (no)
• The schema: (no)
• The default values of configurations: introduced a new default of proxy HTTP connect timeout
• The wire protocol: no
• The rest endpoints: no
• The admin cli options: no
• Anything that affects deployment: no

[Anonymitaet]

@zzzming Thanks for your contribution. For this PR, do we need to update docs?

(The PR template contains info about doc, which helps others know more about the changes. Can you provide doc-related info in this and future PR descriptions? Thanks)

[eolivelli]

@codelipenghui @rdhabalia @merlimat
it would be good to see this in 2.9.0 as it is a critical issue

[eolivelli]

Lgtm

[merlimat]

@zzzming @lhotari @eolivelli this change does not take into consideration that upload and download of very large functions jars can easily take more than 30 sec.

[lhotari]

@zzzming @lhotari @eolivelli this change does not take into consideration that upload and download of very large functions jars can easily take more than 30 sec.

@merlimat ok, what would be a sufficient timeout value?

[merlimat]

Maybe we could try with something like 5min?

[eolivelli]

@merlimat you are right.
We should change the default

@zzzming would you mind sending a new PR?