Issue with empty pop throwing an error at assignSpikes in runSimulationMultiregion

[Fehings]

There is a fix for this, just catch the emptys:

                if ~isempty(regionConnect.dummyNeuronPops{rr}) % don't bother assigning spikes unless there are some to assign!
                        assignSpikes(NeuronModelArr{rr}{regionConnect.dummyNeuronPops{rr}},exportingNeuronSpikes{rgn}{rr}(:,delayAccess{rgn,rr}));
                end

add this in at line 495.

Keeping this open as I need to push this change and sort merge issues and bleh D: I will do this when there is time...