Fixed compilation in profiler.
Fixed compilation in profiler.

It was complaining for std::accumulate() in my laptop with clang.

halfflat/arbor,halfflat/nestmc-proto,eth-cscs/nestmc-proto,halfflat/nestmc-proto,halfflat/arbor,halfflat/nestmc-proto,halfflat/arbor,halfflat/arbor,eth-cscs/nestmc-proto,eth-cscs/nestmc-proto,halfflat/arbor