Bug 259285 - [Viewers] [JFace] bug in snippet 019

Applying fix patch from the bugreport (Still odd behavior)

To reproduce the odd behavior
1. Apply the 'WithFix' patch to JFace snipper 019
2. Move 'Age' or 'Surname' column to the first column.
3. Right click in the left column and add the 'E-mail' column before it.
4. Note how the 'E-mail' column appears as the 3rd column and not in
position 

Change-Id: I314caa2c6612955efbd4aeca7cca9903d97d437e
Signed-off-by: Hendrik Still <hendrik.still@gammas.de>