Revert: "When processing multiple tasks defer uploads until the end"

This reverts commit 2dd58ce.

On second thought no, lets allow the busy loop to parallize as much
as it possibly can. We can always look at refactoring to provide a
continous time frame for GL_ProcessDeferredTasks() spanning all
tasks later on.

doomsday/engine/portable/src/con_busy.c

@@ -267,10 +267,6 @@ void Con_BusyList(BusyTask* tasks, int numTasks)
         mode = task->mode | BUSYF_STARTUP;
         // kludge end
 
-        // Accumulate uploads until the last task completes.
-        if(i < numTasks-1)
-            mode |= BUSYF_NO_UPLOADS;
-
         // Busy mode invokes the worker on our behalf in a new thread.
         task->retVal = Con_Busy(mode, currentTaskName, task->worker, task->workerData);
     }