delete request data sooner

lib/single-file/single-file-core.js

@@ -295,6 +295,7 @@ this.SingleFileCore = this.SingleFileCore || (() => {
 			return Promise.all(resourceURLs.map(async requestKey => {
 				const [resourceURL, asDataURI] = JSON.parse(requestKey);
 				const resourceRequests = this.requests.get(requestKey);
+				this.requests.delete(requestKey);
 				try {
 					const content = await docUtil.getContent(resourceURL, { asDataURI, maxResourceSize: options.maxResourceSize, maxResourceSizeEnabled: options.maxResourceSizeEnabled });
 					indexResource = indexResource + 1;
@@ -308,8 +309,7 @@ this.SingleFileCore = this.SingleFileCore || (() => {
 					indexResource = indexResource + 1;
 					onloadListener({ index: indexResource, url: resourceURL });
 					resourceRequests.forEach(resourceRequest => resourceRequest.reject(error));
-				}
-				this.requests.delete(requestKey);
+				}				
 			}));
 		}
 	}