ProjectMgr: GanttChart fails, in case of dependencies for tasks

the problen is in line 127:
taskInfo.preDecessor = latestTaskIds
This line causes brackets around ids (e.g.: [10098] )
And these brackets cannot be processed by jsgantt.
So in case of dependencies the ganttchart will not be displayed.

To fix it, the ids could be processed in a loop:

count = 0;
if (UtilValidate.isNotEmpty(latestTaskIds)) {
  taskInfo.preDecessor = "";
    for (i in latestTaskIds) {
   if (count>0) {
    taskInfo.preDecessor = taskInfo.preDecessor +", " + i; 
   } else {
   taskInfo.preDecessor = taskInfo.preDecessor + i;
  }
  count ++;
  }
}