[vim] assume 7.3+
change
commit 2d21bd1b4759c8bdfacfbd112afdd9846a3eaf80
author Alpha Chen <alpha.chen@gmail.com>
date
parent 7b7c70c8 
diff --git a/.vimrc b/.vimrc
index 4e2e409e..9a3450a1 100644
--- a/.vimrc
+++ b/.vimrc
@@ -225,10 +225,8 @@ if has("gui_running")
   set mousehide
 end
 
-if v:version >= 703
-  set undofile
-  set undodir=$HOME/.vim_undo//
-endif
+set undofile
+set undodir=$HOME/.vim_undo//
 
 if filereadable(glob("~/.vimrc.local"))
   source ~/.vimrc.local