Fixing CurlLinkChecker::checkLink() using incorrect visibility
Fixing CurlLinkChecker::checkLink() using incorrect visibility

GOVTNZ/silverstripe-externallinks,blpraveen/silverstripe-brokenlinks,DIA-NZ/silverstripe-externallinks,GOVTNZ/silverstripe-externallinks,DIA-NZ/silverstripe-externallinks,blpraveen/silverstripe-brokenlinks,silverstripe-labs/silverstripe-externallinks,silverstripe-labs/silverstripe-externallinks