[fix] only make GET requests in parallel

Author: doublerebel

src/spine.ajax.iced

@@ -94,6 +94,7 @@ class Base
  settings.error = rv.id('error').defer xhr, statusText, error
 
  request = (next) ->
+ Ajax.pipeliner.window = if settings.type is 'GET' then Ajax.max else 1
  xhr = new $.ajax(settings)
  await rv.wait defer status
  switch status