Updated Sortable JS plugin

CHANGELOG.md

@@ -22,6 +22,7 @@ Please view this file on the master branch, on stable branches it's out of date.
 - Escape ref and path for relative links !6050 (winniehell)
 - Fixed link typo on /help/ui to Alerts section. !6915 (Sam Rose)
 - Fix filtering of milestones with quotes in title (airatshigapov)
+- Fix issue boards dragging bug in Safari
 - Refactor less readable existance checking code from CoffeeScript !6289 (jlogandavison)
 - Update mail_room and enable sentinel support to Reply By Email (!7101)
 - Add task completion status in Issues and Merge Requests tabs: "X of Y tasks completed" (!6527, @gmesalazar)

app/assets/stylesheets/pages/boards.scss

@@ -12,6 +12,10 @@
   opacity: 1!important;
 
   * {
+    -webkit-user-select: none;
+    -moz-user-select: none;
+    -ms-user-select: none;
+    user-select: none;
     // !important to make sure no style can override this when dragging
     cursor: -webkit-grabbing!important;
     cursor: grabbing!important;