HighwaySystem::route_integrity potential minor speedup

[yakra]

DataProcessing/siteupdate/cplusplus/classes/HighwaySystem/route_integrity.cpp

Lines 57 to 58 in 38da77b

	#define q cr->roots[i-1]
	#define r cr->roots[i]

Declaring these as references can potentially save a little arithmetic and dereferencing.
Will the savings add up?