Remove improper _POSIX_C_SOURCE check. (#300)
Remove improper _POSIX_C_SOURCE check. (#300)

Remove improper _POSIX_C_SOURCE check.
Fixes #299.
halfflat/nestmc-proto,eth-cscs/nestmc-proto,halfflat/arbor,eth-cscs/nestmc-proto,halfflat/arbor,halfflat/nestmc-proto,halfflat/arbor,halfflat/arbor,halfflat/nestmc-proto,halfflat/arbor,eth-cscs/nestmc-proto