Fix override on vim startup

Relay only on indent_guides_enable_on_vim_startup

autoload/indent_guides.vim

@@ -19,7 +19,7 @@ endfunction
 " other buffers and windows.
 "
 function! indent_guides#process_autocmds() abort
-  if indent_guides#getvar('indent_guides_autocmds_enabled')
+  if indent_guides#getvar('indent_guides_enable_on_vim_startup')
     call indent_guides#enable()
   else
     call indent_guides#disable()
@@ -30,7 +30,7 @@ endfunction
 " Enables the indent guides for the current buffer
 "
 function! indent_guides#enable() abort
-  let b:indent_guides_autocmds_enabled = 1
+  let b:indent_guides_enable_on_vim_startup = 1
 
   if &diff || indent_guides#exclude_filetype()
     call indent_guides#clear_matches()
@@ -64,7 +64,7 @@ endfunction
 " entering it.
 "
 function! indent_guides#disable() abort
-  let b:indent_guides_autocmds_enabled = 0
+  let b:indent_guides_enable_on_vim_startup = 0
   call indent_guides#clear_matches()
 endfunction
 

plugin/indent_guides.vim

@@ -44,7 +44,6 @@ function s:InitVariable(var, value)
 endfunction
 
 " Fixed global variables
-let g:indent_guides_autocmds_enabled         = 0
 let g:indent_guides_color_hex_pattern        = '#[0-9A-Fa-f]\{6\}'
 let g:indent_guides_color_hex_guibg_pattern  = 'guibg=\zs' . g:indent_guides_color_hex_pattern . '\ze'
 let g:indent_guides_color_name_guibg_pattern = "guibg='\\?\\zs[0-9A-Za-z ]\\+\\ze'\\?"
@@ -81,11 +80,6 @@ nnoremap <unique><script> <Plug>IndentGuidesDisable :IndentGuidesDisable<CR>
 augroup indent_guides
   autocmd!
 
-  if g:indent_guides_enable_on_vim_startup
-    let g:indent_guides_autocmds_enabled = 1
-    autocmd VimEnter * :IndentGuidesEnable
-  endif
-
   autocmd BufEnter,WinEnter,FileType * call indent_guides#process_autocmds()
   if (v:version == 704 && has('patch786')) || (v:version > 704)
     autocmd OptionSet tabstop,shiftwidth,expandtab call indent_guides#process_autocmds()