[sparql] Enable user to set a custom useragent
To query some api (wikidata for instance), one may have to give a specific useragent. With this patch, the user is allowed to use the useragent of his/her choice, or the default one.
To query some api (wikidata for instance), one may have to give a specific useragent. With this patch, the user is allowed to use the useragent of his/her choice, or the default one.