requirements: bump invenio-files-rest to allow range requests

Author: zzacharo

requirements.txt

@@ -86,7 +86,7 @@ invenio-cache==1.3.1
 invenio-celery==1.3.2
 invenio-config==1.0.4
 invenio-db==1.3.1
-invenio-files-rest==2.2.4
+invenio-files-rest==2.4.0
 invenio-formatter==2.0.4
 invenio-i18n==2.2.0
 invenio-iiif==1.2.0