Only lock in map update timer when available.
Only lock in map update timer when available.

Only lock the mutex cs_main in the UI map update timer when the lock is
immediately available and skip update ticks if this is not the case.

chronokings/huntercoin,chronokings/huntercoin,domob1812/huntercoin,chronokings/huntercoin,wiggi/huntercoin,domob1812/huntercoin,wiggi/huntercoin,chronokings/huntercoin,fsb4000/huntercoin,domob1812/huntercoin,fsb4000/huntercoin,wiggi/huntercoin,fsb4000/huntercoin,wiggi/huntercoin,fsb4000/huntercoin,domob1812/huntercoin