configure.ac: bump pthread-stubs requirement

On platforms that require it, we bump the requirement to 0.4 or later.
Due to an issue with the project [design] any version earlier than it,
is bound to cause issues. For the specifics see the pthread-stubs README

Cc: Uli Schlachter <psychon@znc.in>
Cc: Jonathan Gray <jsg@jsg.id.au>
Cc: Jean-Sébastien Pédron <dumbbell@FreeBSD.org>
Cc: François Tigeot <ftigeot@wolfpond.org>
Cc: Tobias Nygren <tnn@NetBSD.org>
Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
diff --git a/configure.ac b/configure.ac
index 2adf399..8c9d756 100644
--- a/configure.ac
+++ b/configure.ac
@@ -812,7 +812,7 @@
 esac
 
 if test "x$pthread_stubs_possible" = xyes; then
-    PKG_CHECK_MODULES(PTHREADSTUBS, pthread-stubs)
+    PKG_CHECK_MODULES(PTHREADSTUBS, pthread-stubs >= 0.4)
     AC_SUBST(PTHREADSTUBS_CFLAGS)
     AC_SUBST(PTHREADSTUBS_LIBS)
 fi