Ensure jobstart on_exit runs when waiting

Resolves: https://github.com/tpope/vim-fugitive/issues/1857

autoload/fugitive.vim

@@ -263,6 +263,9 @@ 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')
+      sleep 1m
+    endif
   else
     let sleep = has('patch-8.2.2366') ? 'sleep! 1m' : 'sleep 1m'
     for job in jobs