[z2259] Some small changes

* Replace Expansion related magic numbers
* Remove an unneeded double line. Thanks to Ambal for pointing
* Add additional check for DK starting zones map file

Signed-off-by: Schmoozerd <schmoozerd@cmangos>

(based on commit [12364] - 90e787f)

(based on commit [s1897] - acc883d)

Signed-off-by: Xfurry <xfurry@scriptdev2.com>