Added check for sys/sysctl.h.

diff --git a/configure b/configure
index 299a97e..9c9f9d8 100755
--- a/configure
+++ b/configure
@@ -10474,6 +10474,7 @@
 
 
 
+
 for ac_header in \
 	arpa/inet.h \
 	arpa/nameser.h \
@@ -10528,6 +10529,7 @@
 	sys/statfs.h \
 	sys/strtio.h \
 	sys/syscall.h \
+	sys/sysctl.h \
 	sys/time.h \
 	sys/user.h \
 	sys/v86.h \