plug upgrade

vim/.vim/autoload/plug.vim

@@ -935,7 +935,7 @@ function! s:prepare(...)
     call s:new_window()
   endif
 
-  nnoremap <silent> <buffer> q  :if b:plug_preview==1<bar>pc<bar>endif<bar>bd<cr>
+  nnoremap <silent> <buffer> q :call <SID>close_pane()<cr>
   if a:0 == 0
     call s:finish_bindings()
   endif
@@ -957,6 +957,15 @@ function! s:prepare(...)
   endif
 endfunction
 
+function! s:close_pane()
+  if b:plug_preview == 1
+    pc
+    let b:plug_preview = -1
+  else
+    bd
+  endif
+endfunction
+
 function! s:assign_name()
   " Assign buffer name
   let prefix = '[Plugins]'
@@ -1532,7 +1541,7 @@ while 1 " Without TCO, Vim stack is bound to explode
     let [error, _] = s:git_validate(spec, 0)
     if empty(error)
       if pull
-        let cmd = ['git', 'fetch']
+        let cmd = s:git_version_requirement(2) ? ['git', '-c', 'credential.helper=', 'fetch'] : ['git', 'fetch']
         if has_tag && !empty(globpath(spec.dir, '.git/shallow'))
           call extend(cmd, ['--depth', '99999999'])
         endif