Enable no-irregular-whitespace lint

A couple comments contained non-breaking spaces (I think), which I
replaced with regular spaces.

.eslintrc.js

@@ -69,7 +69,6 @@ module.exports = {
         'no-constant-condition': 'off',
         'no-empty': 'off',
         'no-unsafe-finally': 'off',
-        'no-dupe-keys': 'off',
-        'no-irregular-whitespace': 'off'
+        'no-dupe-keys': 'off'
     }
 };