[SP3] Fixed displaying patch categories (bsc#1174390)

[lslezak]

The Bug

• https://bugzilla.suse.com/show_bug.cgi?id=1174390
• In some special cases the patch category was not displayed. It works fine in a VirtualBox VM or at bare metal, I could only reproduce it inside a KVM VM running YaST in KDE desktop.
• But because of the nature of the bug it could randomly happen basically anywhere (see below)

The Fix

• It turned out that the code used a wrong index column which is not used anymore and which was not even initialized.
• It basically used any random value found in that part of the memory
• Besides using the correct column index I added an initialization so the variable does not have undefined (random) value anymore to avoid similar problems

TODO

• In the future we should remove all that unused code and variables, they can only make troubles like this... There is also quite a lot of commented out code.

[shundhammer]

LGTM

[lslezak]

Sumitted manually in https://build.suse.de/request/show/248766