Fix #2094, reject blob (or any non-http(s)) images detected in the document
Fix #2094, reject blob (or any non-http(s)) images detected in the document

fzzzy/pageshot,mozilla-services/screenshots,mozilla-services/pageshot,mozilla-services/screenshots,mozilla-services/screenshots,mozilla-services/screenshots,fzzzy/pageshot,mozilla-services/pageshot,mozilla-services/pageshot,fzzzy/pageshot,mozilla-services/pageshot,fzzzy/pageshot