elm: apply the same fix we needed in entry to other scrollable widgets

elm: apply the same fix we needed in entry to other scrollable widgets

this here is the same effect as in my previous commit:
When re retheme a object, we need to reset the signals, otherwise there
would be wrongly displayed scrollbars.

This fixes wrong scrollbars in enlightenment.

Differential Revision: https://phab.enlightenment.org/D10628