Revert "Remove deprecated :UltiSnipsAddFiletypes call"

This reverts commit fcd1178.

Author: tpope

autoload/rails.vim

@@ -4512,6 +4512,9 @@ function! s:BufSettings()
       call self.setvar('surround_69',  "\1expr: \1\rend")
       call self.setvar('surround_101', "\r\nend")
     endif
+    if exists(':UltiSnipsAddFiletypes') == 2
+      UltiSnipsAddFiletypes rails
+    endif
   elseif ft =~# 'yaml\>' || fnamemodify(self.name(),':e') ==# 'yml'
     call self.setvar('&define',self.define_pattern())
   elseif ft =~# '^eruby\>'