Change the concurrent upload limit to less than 10

Signed-off-by: szaimen <szaimen@e.mail.de>

apps/files/js/file-upload.js

@@ -902,7 +902,7 @@ OC.Uploader.prototype = _.extend({
 				dropZone: options.dropZone, // restrict dropZone to content div
 				autoUpload: false,
 				sequentialUploads: false,
-				limitConcurrentUploads: 10,
+				limitConcurrentUploads: 4,
 				/**
 				 * on first add of every selection
 				 * - check all files of originalFiles array with files in dir