Local server address

[johnd0e]

IITC-Button/scripts/defaults.js

Line 5 in a27d8fc

'local': "http://127.0.0.1:8000"

1. When entering address in settings - it get accepted only after removing 'http://' part.
   It is not obvious and generally wrong.

2. When entering wrong address - text become red. But it is not clear enough, e.g. when it's initially red, or for color-blind person.
   So better output error message to status line.

3. Wrong address is not stored. But what if it is not 'wrong', but just temporary unavailable?
   I suppose any user-entered value should be stored (and empty should be converted to default).

4. Instead of 127.0.0.1 better use localhost.
   BTW, in recent version python server defaulted to ip6 (::1), so localhost would be more robust.