Fix race condition on nvim 0.4

I could have sworn this wasn't necessary on 0.4, which is why I added
the extra clause, but I can consistently reproduce E716 now.

Resolves: https://github.com/tpope/vim-fugitive/issues/1881

autoload/fugitive.vim

@@ -263,7 +263,7 @@ function! fugitive#Wait(job_or_jobs, ...) abort
   if exists('*jobwait')
     call map(copy(jobs), 'chanclose(v:val, "stdin")')
     call jobwait(jobs, timeout_ms)
-    if len(jobs) && has('nvim-0.5')
+    if len(jobs)
       sleep 1m
     endif
   else