fix: only set keep-alive when not exists
- only set Keep-Alive once
- set Keep-Alive with correct ms
fix: https://github.com/nodejs/node/pull/34561#discussion_r484192560
Checklist
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make -j4 test
(UNIX), orvcbuild test
(Windows) passes -
tests and/or benchmarks are included -
documentation is changed or added -
commit message follows commit guidelines