[vim] fix Ruby perf issue
See vim-ruby/vim-ruby#243
change
commit bd58fa071efd11e34f51b8a429503a994b478816
author Alpha Chen <alpha.chen@gmail.com>
date
parent bafaafe2 
diff --git a/.vim/after/ftplugin/ruby.vim b/.vim/after/ftplugin/ruby.vim
index ce07d87a..1684cd67 100644
--- a/.vim/after/ftplugin/ruby.vim
+++ b/.vim/after/ftplugin/ruby.vim
@@ -1,2 +1,5 @@
+" https://github.com/vim-ruby/vim-ruby/issues/243
+set regexpengine=1
+
 highlight rubyDefine ctermbg=235
 set foldmethod=syntax