apacheGH-1611: supply initial value for acceptHeaderGraph to requestConfig

Author: OyvindLGjesdal

jena-fuseki2/jena-fuseki-ui/src/views/dataset/Query.vue

@@ -296,6 +296,7 @@ export default {
             showQueryButton: true,
             resizeable: true,
             requestConfig: {
+              acceptHeaderGraph : this.contentTypeGraph,
               endpoint: this.$fusekiService.getFusekiUrl(this.currentDatasetUrl)
             },
             createShareableLink: curriedCreateShareableLink