Allow progname 'vimx'

"I you are running Redhat/CentOS, you can install the vim-X11 package
(if you have gvim then this is already installed). This provides the
vimx command, which is a console version of Vim with X11-clipboard
support."

plugin/startify.vim

@@ -10,7 +10,7 @@ let g:loaded_startify = 1
 
 augroup startify
   autocmd VimEnter *
-        \ if !argc() && (line2byte('$') == -1) && (v:progname =~? '^[gm]\=vim\%[\.exe]$') |
+        \ if !argc() && (line2byte('$') == -1) && (v:progname =~? '^[gm]\=vimx\=\%[\.exe]$') |
         \   call startify#insane_in_the_membrane() |
         \ endif |
         \ autocmd! startify VimEnter