Description of problem:
When a picture is zoomed in to a size that exceeds the window size, it is not possible to scroll down the picture.

Version-Release number of selected component (if applicable):
eom-1.10.0-1.fc22.x86_64.rpm

How reproducible:
Every time.

Steps to Reproduce:
1. Open a picture in eom.
2. Click the "Zoom in" button until only part of the picture is visible. 
3. Try to drag the vertical scroll bar slider down in order to see the lower part of the picture (or try to turn the mouse wheel when the pointer is placed on top of the vertical scroll bar).

Actual results:
Nothing happens.

Expected results:
The image should scroll.

Additional info:
This has worked properly since the times of GNOME 2 and eog; also works properly with eom up to F21 incl (e.g., eom-1.8.1-1.fc21.x86_64). It is expected to work both ways - by either dragging the scroll slider down, or by scrolling the mouse wheel when the pointer is on top of the scroll bar.