dspace.cfg: remove old webui.itemlist.browse.* property

The webui.itemlist.browse.* properties are no longer used in DSpace
7.

dspace/config/dspace.cfg

@@ -1478,14 +1478,8 @@ log.report.dir = ${dspace.dir}/log
 # they are listed below is the priority in which they will be used (so a combination
 # of an index name and sort name will take precedence over just the browse name).
 #
-# webui.itemlist.browse.<index name>.sort.<sort name>.columns
 # webui.itemlist.sort.<sort name>.columns
-# webui.itemlist.browse.<browse name>.columns
 # webui.itemlist.<sort or index name>.columns
-#
-# In the last case, a sort option name will always take precedence over a browse
-# index name. Note also, that for any additional columns you list, you will need to
-# ensure there is an itemlist.<field name> entry in the messages file.
 
 ##### SFX Server (OpenURL) #####