restore building --test-build-rtsig and --test-build-eventport on FreeBSD 6
diff --git a/src/event/modules/ngx_rtsig_module.c b/src/event/modules/ngx_rtsig_module.c
index c753854..6020936 100644
--- a/src/event/modules/ngx_rtsig_module.c
+++ b/src/event/modules/ngx_rtsig_module.c
@@ -11,8 +11,14 @@
#if (NGX_TEST_BUILD_RTSIG)
-#define F_SETSIG 10
+#ifdef SIGRTMIN
#define si_fd _reason.__spare__.__spare2__[0]
+#else
+#define SIGRTMIN 33
+#define si_fd __spare__[0]
+#endif
+
+#define F_SETSIG 10
#define KERN_RTSIGNR 30
#define KERN_RTSIGMAX 31