datafeeder config - remove fqdn

[fvanderbiest]

@pmauduit reports the fqdn is useless on line

datadir/datafeeder/frontend-config.json

Line 26 in 7f82a8c

"thesaurusUrl": "https://georchestra.mydomain.org/geonetwork/srv/api/registries/vocabularies/search?type=CONTAINS&thesaurus=external.theme.httpinspireeceuropaeutheme-theme&rows=200&q=${q}&uri=**&lang=${lang}"