Sanitize urls with single quotation marks

This fixes behavior for URLs with single quotes within them.
The behavior for a url like `https://severalglamorousthing.426729.repl.co/google's%20logo.png` would be no background at all; the CSS rule would change to `background-image: url((unknown));`.
This fixes the problem and adds `\` to every `'` in the image url.
The behavior of the repo with this fix would be a conversion of the url provided above to  `https://severalglamorousthing.426729.repl.co/google\'s%20logo.png`, which can be put into `\`url('${url}')\`` without breaking the CSS rule.

src/ui/component/cardMedia/view.jsx

@@ -18,7 +18,7 @@ class CardMedia extends React.PureComponent<Props> {
     }
 
     const url = thumbnail || Placeholder;
-    return <div style={{ backgroundImage: `url('${url}')` }} className={className} />;
+    return <div style={{ backgroundImage: `url('${url.replace(/'/g,"\\'")}')` }} className={className} />;
   }
 }