Add workaround for Visual C++ issue with std::array in debug
Add workaround for Visual C++ issue with std::array in debug

If Visual C++ _ITERATOR_DEBUG_LEVEL > 0, then
accessing std::array<char[N], M> elements via reference to const
causes compilation error:

...\msvc\14.10.25017\include\array(181): error C2440: 'return': cannot convert from 'const char *' to 'const char (&)[256]'

Alternative workaround is to remove const qualifier from the GetClassName method.

bjtaylor1/osrm-backend,neilbu/osrm-backend,frodrigo/osrm-backend,KnockSoftware/osrm-backend,oxidase/osrm-backend,Project-OSRM/osrm-backend,Project-OSRM/osrm-backend,neilbu/osrm-backend,deniskoronchik/osrm-backend,yuryleb/osrm-backend,frodrigo/osrm-backend,Project-OSRM/osrm-backend,yuryleb/osrm-backend,oxidase/osrm-backend,oxidase/osrm-backend,bjtaylor1/osrm-backend,yuryleb/osrm-backend,bjtaylor1/osrm-backend,deniskoronchik/osrm-backend,felixguendling/osrm-backend,bjtaylor1/osrm-backend,neilbu/osrm-backend,KnockSoftware/osrm-backend,KnockSoftware/osrm-backend,frodrigo/osrm-backend,yuryleb/osrm-backend,deniskoronchik/osrm-backend,KnockSoftware/osrm-backend,Project-OSRM/osrm-backend,felixguendling/osrm-backend,felixguendling/osrm-backend,frodrigo/osrm-backend,oxidase/osrm-backend,neilbu/osrm-backend,deniskoronchik/osrm-backend