Revert "Add a tag alias for PmenuSel"

Author: k-takata

tools/tag_aliases.vim

@@ -1,4 +1,3 @@
 let g:makehtml_tag_aliases = {
   \ '=~': 'expr-=~',
-  \ 'PmenuSel': 'hl-PmenuSel',
   \ }