Remove fugitive error message when opening dirvish

Receiving this message with recent updates to dirvish and fugitive:

    Third party code is using fugitive#detect() which has been removed.
    Contact the author if you have a reason to still use it

Removing our autocommand to use fugitive in dirvish stopped this error.
This was seldom used anyway.

vim/autoload/plug.vim

@@ -251,7 +251,7 @@ endfunction
 
 function! plug#end()
   if !exists('g:plugs')
-    return s:err('Call plug#begin() first')
+    return s:err('plug#end() called without calling plug#begin() first')
   endif
 
   if exists('#PlugLOD')

vim/settings/filebrowser.vim

@@ -15,9 +15,6 @@ let g:dirvish_relative_paths = (v:version <= 703 ? 1 : 0)
 augroup dirvishCustomisation
   autocmd!
 
-  " Allow fugitive.vim commands in dirvish buffers.
-  autocmd FileType dirvish call fugitive#detect(@%)
-
   " Add/Adjust mappings.
   " - 'o' to (o)pen and 'i' to spl(i)t.
   " - Add, Copy, Delete, Rename with 'ma', 'mc', 'md', 'mr'.

vim/settings/filetype-specifics.vim

@@ -11,4 +11,4 @@ au BufEnter *.conf,*.ini setlocal textwidth=0
 au BufNewFile,BufRead *.tag setlocal ft=javascript
 
 " Add spelling to markdown files
-autocmd BufRead,BufNewFile *.md setlocal spell
+au FileType markdown setlocal spell