fix: do not reuse connections per default

[clementnuss]

stop reusing connections per default, by modifying the http.Transport DisableKeepAlive field to true per default. Can be overriden through setting KUBENURSE_REUSE_CONNECTIONS env var to "true"

This will be a minor change, as the results and behaviour of Kubenurse is modified consequently.

[clementnuss]

@zbindenren @djboris9 what do you think ?

the effect on the number of open file descriptor/goroutines is really interesting. the http request duration also starts to be more interesting !

do you agree that this mode should be the default ?

[github-actions[bot]]

Pull Request Test Coverage Report for Build 7584865362

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.3%) to 76.683%

---

Totals
Change from base Build 7382603208:	-0.3%
Covered Lines:	467
Relevant Lines:	609

---

💛 - Coveralls

[zbindenren]

@zbindenren @djboris9 what do you think ?

the effect on the number of open file descriptor/goroutines is really interesting. the http request duration also starts to be more interesting !

do you agree that this mode should be the default ?

@clementnuss LGTM 👍