rdf validate: fix comparisons with empty frames#122

Ostrzyciel merged 2 commits intomainJelly-RDF/cli:mainfrom

GH-121-rdf-validate-skips-empty-frames-if-they-occur-before-the-first-stream-with-stream-optionsJelly-RDF/cli:GH-121-rdf-validate-skips-empty-frames-if-they-occur-before-the-first-stream-with-stream-optionsCopy head branch name to clipboard