[TASK] Remove allow_url_fopen check since ext:solr uses cURL for decades now

[josefglatz]

trafficstars

Solr-ext uses cURL and setting allow_url_fopen to off does not break the indexing in any of our scenarios.

I suggest to remove the check if there are no other reasons to leave this check.

[spoonerWeb]

As EXT:solr use Guzzle for indexing pages there is no need for a check anymore imho.