bug #31569 [HttpClient] Only use CURLMOPT_MAX_HOST_CONNECTIONS & CURL_VERSION_HTTP2 if defined (GawainLynch)
bug #31569 [HttpClient] Only use CURLMOPT_MAX_HOST_CONNECTIONS & CURL_VERSION_HTTP2 if defined (GawainLynch)

This PR was merged into the 4.3 branch.

Discussion
----------

[HttpClient] Only use CURLMOPT_MAX_HOST_CONNECTIONS & CURL_VERSION_HTTP2 if defined

| Q             | A
| ------------- | ---
| Branch?       | 4.3
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets |
| License       | MIT
| Doc PR        |

Regards the constants:

 - CURLMOPT_MAX_HOST_CONNECTIONS is available since PHP 7.0.7 and cURL 7.30.0
 - CURL_VERSION_HTTP2 is available since PHP 5.5.24 and 5.6.8 and cURL 7.33.0

Errors triggered:

> Use of undefined constant CURLMOPT_MAX_HOST_CONNECTIONS - assumed 'CURLMOPT_MAX_HOST_CONNECTIONS'
> in vendor/symfony/http-client/CurlHttpClient.php (line 73)

> Use of undefined constant CURL_VERSION_HTTP2 - assumed 'CURL_VERSION_HTTP2'
> in vendor/symfony/http-client/CurlHttpClient.php (line 191)

Commits
-------

4ea7283138 [HttpClient] Only use CURLMOPT_MAX_HOST_CONNECTIONS & CURL_VERSION_HTTP2 if defined

jvasseur/symfony,gonzalovilaseca/symfony,fabpot/symfony,Taluu/symfony,lstrojny/symfony,pierredup/symfony,phramz/symfony,Tobion/symfony,voronkovich/symfony,zerkms/symfony,chalasr/symfony,gonzalovilaseca/symfony,shieldo/symfony,damienalexandre/symfony,MatTheCat/symfony,ogizanagi/symfony,lstrojny/symfony,mweimerskirch/symfony,shieldo/symfony,oleg-andreyev/symfony,symfony/symfony,fabpot/symfony,nicolas-grekas/symfony,phramz/symfony,OskarStark/symfony,dmaicher/symfony,pierredup/symfony,HeahDude/symfony,Slamdunk/symfony,fabpot/symfony,ogizanagi/symfony,sgehrig/symfony,ro0NL/symfony,Koc/symfony,tucksaun/symfony,andreia/symfony,teohhanhui/symfony,docteurklein/symfony,derrabus/symfony,hhamon/symfony,lyrixx/symfony,symfony/symfony,teohhanhui/symfony,zorn-v/symfony,andreia/symfony,Tobion/symfony,Taluu/symfony,oleg-andreyev/symfony,voronkovich/symfony,localheinz/symfony,Deamon/symfony,Slamdunk/symfony,kbond/symfony,alekitto/symfony,vincentaubert/symfony,jderusse/symfony,yceruto/symfony,dmaicher/symfony,Koc/symfony,curry684/symfony,stof/symfony,MatTheCat/symfony,yceruto/symfony,Deamon/symfony,derrabus/symfony,ogizanagi/symfony,fabpot/symfony,jderusse/symfony,zcodes/symfony,vincentaubert/symfony,shieldo/symfony,nicolas-grekas/symfony,lyrixx/symfony,mpdude/symfony,maidmaid/symfony,smatyas/symfony,zcodes/symfony,Deamon/symfony,docteurklein/symfony,romaricdrigon/symfony,Slamdunk/symfony,mnapoli/symfony,ragboyjr/symfony,jakzal/symfony,pyrech/symfony,zorn-v/symfony,Deamon/symfony,phramz/symfony,d-ph/symfony,sgehrig/symfony,zorn-v/symfony,pierredup/symfony,vincentaubert/symfony,arjenm/symfony,smatyas/symfony,bendavies/symfony,d-ph/symfony,1ed/symfony,jakzal/symfony,romaricdrigon/symfony,kbond/symfony,kbond/symfony,mnapoli/symfony,OskarStark/symfony,oleg-andreyev/symfony,Tobion/symfony,damienalexandre/symfony,xabbuh/symfony,chalasr/symfony,mpdude/symfony,arjenm/symfony,Taluu/symfony,Simperfit/symfony,Nyholm/symfony,jvasseur/symfony,jderusse/symfony,symfony/symfony,Simperfit/symfony,yceruto/symfony,jvasseur/symfony,lstrojny/symfony,mnapoli/symfony,teohhanhui/symfony,stof/symfony,OskarStark/symfony,zerkms/symfony,ro0NL/symfony,xabbuh/symfony,xabbuh/symfony,gonzalovilaseca/symfony,HeahDude/symfony,1ed/symfony,sgehrig/symfony,gonzalovilaseca/symfony,pyrech/symfony,smatyas/symfony,symfony/symfony,nicolas-grekas/symfony,sgehrig/symfony,smatyas/symfony,curry684/symfony,mweimerskirch/symfony,derrabus/symfony,xabbuh/symfony,tucksaun/symfony,hhamon/symfony,arjenm/symfony,paradajozsef/symfony,Nyholm/symfony,voronkovich/symfony,MatTheCat/symfony,MatTheCat/symfony,mpdude/symfony,stof/symfony,teohhanhui/symfony,damienalexandre/symfony,1ed/symfony,dmaicher/symfony,garak/symfony,alekitto/symfony,nicolas-grekas/symfony,ragboyjr/symfony,1ed/symfony,oleg-andreyev/symfony,ro0NL/symfony,docteurklein/symfony,dmaicher/symfony,tgalopin/symfony,Tobion/symfony,Simperfit/symfony,localheinz/symfony,romaricdrigon/symfony,bendavies/symfony,Koc/symfony,mnapoli/symfony,jvasseur/symfony,mweimerskirch/symfony,pyrech/symfony,curry684/symfony,lyrixx/symfony,tucksaun/symfony,Simperfit/symfony,ragboyjr/symfony,paradajozsef/symfony,paradajozsef/symfony,hhamon/symfony,Taluu/symfony,yceruto/symfony,chalasr/symfony,maidmaid/symfony,voronkovich/symfony,Koc/symfony,HeahDude/symfony,zcodes/symfony,ro0NL/symfony,Slamdunk/symfony,andreia/symfony,vincentaubert/symfony,maidmaid/symfony,Nyholm/symfony,arjenm/symfony,zorn-v/symfony,localheinz/symfony,andreia/symfony,Simperfit/symfony,HeahDude/symfony,tgalopin/symfony,pyrech/symfony,bendavies/symfony,curry684/symfony,hhamon/symfony,garak/symfony,shieldo/symfony,jakzal/symfony,tgalopin/symfony,bendavies/symfony,jakzal/symfony,Nyholm/symfony,smatyas/symfony,Deamon/symfony,OskarStark/symfony,garak/symfony,pierredup/symfony,paradajozsef/symfony,mpdude/symfony,docteurklein/symfony,d-ph/symfony,chalasr/symfony,d-ph/symfony,maidmaid/symfony,romaricdrigon/symfony,mweimerskirch/symfony,phramz/symfony,stof/symfony,ragboyjr/symfony,zcodes/symfony,derrabus/symfony,garak/symfony,ogizanagi/symfony,zerkms/symfony,localheinz/symfony,jderusse/symfony,mnapoli/symfony,zerkms/symfony,damienalexandre/symfony,kbond/symfony,docteurklein/symfony,tgalopin/symfony,tucksaun/symfony,lyrixx/symfony,alekitto/symfony,mweimerskirch/symfony,alekitto/symfony