block_timings from sdp are never used if sdp is a zip archive

[vasdommes]

exists(sdp_block_timings_path) will always return false if sdp_path is a zip file (not a directory):

sdpb/src/sdp_solve/Block_Info/read_block_costs.cxx

Lines 13 to 14 in 3019fcd

	const boost::filesystem::path sdp_block_timings_path(sdp_path
	/ "block_timings"),