unbreak OpenBSD after #3937

fix FNM_PATHNAME and FNM_NOESCAPE values.

(backport <#3983>)
(cherry picked from commit 1f68792)

src/unix/mod.rs

@@ -322,6 +322,7 @@ cfg_if! {
  target_os = "macos",
  target_os = "freebsd",
  target_os = "android",
+ target_os = "openbsd",
  ))] {
  pub const FNM_PATHNAME: c_int = 1 << 1;
  pub const FNM_NOESCAPE: c_int = 1 << 0;