gui: Defer jsTree initialisation until next digest cycle (fixes #4738)

gui/default/syncthing/core/syncthingController.js

@@ -1996,6 +1996,7 @@ angular.module('syncthing.core')
                         });
 
                     $q.all([dataReceived, modalShown.promise]).then(function() {
+                        $timeout(function(){
                             if (closed) {
                                 resetRestoreVersions();
                                 return;
@@ -2107,6 +2108,7 @@ angular.module('syncthing.core')
                                 });
                             });
                         });
+                    });
                 }
             };
         }