Removing .DS_Store rule as it is included in global rules

Signed-off-by: Ryan Shrum <ryan@ehousestudio.com>

CraftCMS.gitignore

@@ -1,5 +1,3 @@
-.DS_Store
-
 # Craft Storage (cache) [http://buildwithcraft.com/help/craft-storage-gitignore]
 /craft/storage/*
 !/craft/storage/logo/*