Updated m4/ax_pthread.m4
Updated m4/ax_pthread.m4

dstehle/fplll,fplll/fplll,cr-marcstevens/fplll,fplll/fplll,dstehle/fplll,fplll/fplll,cr-marcstevens/fplll,cr-marcstevens/fplll,dstehle/fplll,cr-marcstevens/fplll,fplll/fplll,fplll/fplll