Fix XSS issue when URL contains characters that have to be escaped
Fix XSS issue when URL contains characters that have to be escaped

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