[Optimization] It's no need to start the dispatch cycle going if the outbound...

[Optimization] It's no need to start the dispatch cycle going if the outbound queue was not previously empty.

If the outbound queue was not previpusly empty, it indicates that the connection's pipe is full.We will try start the next dispatch cycle for this connection in "doDispatchCycleFinishedCommand".
This follows "enqueueDispatchEntriesLocked".

Test: none
Change-Id: I7736c2bfdb13c35a51b74c46ada7b0f562fecfd9