Fix crash on seeing shop which I introduced in r8742. Fixes [2536472].

git-svn-id: https://crawl-ref.svn.sourceforge.net/svnroot/crawl-ref/trunk@8775 c06c8d41-db1a-0410-9941-cceddc491573

Created by  haranp  on January 26, 2009
FF7PTO3XTKFUDF5JF43O7HFH6QNFD3AYQ3M35E3RNGABNL3KNNXQC
Change contents