Set rarity of the slow healing mutation to 0. It is now only available

to Deep Dwarves.

git-svn-id: https://crawl-ref.svn.sourceforge.net/svnroot/crawl-ref/trunk@10606 c06c8d41-db1a-0410-9941-cceddc491573

Created by  dploog  on August 26, 2009
KEJI3QQHGJHXA6FFZ74RIVVAX7CP6Q5RWQCVVYT6UKVCNETIDRCQC
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