Fix regression for error message lineheight (since #113, closes #122) (#123)

Author: Gustl22

src/components/ColorBox/index.jsx

@@ -80,7 +80,7 @@ const useStyles = makeStyles(theme => ({
   },
   colorboxError: {
     color: '#f44336',
-    lineHeight: 36.5,
+    lineHeight: '36.5px',
   },
 }));