package/sshguard: need threads

Fixes:
 - http://autobuild.buildroot.net/results/01fb32fdb21c60ffece09ea5e7ba7b58d989ed76/

Signed-off-by: Pierre-Jean Texier <pjtexier@koncepto.io>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/sshguard/Config.in

@@ -1,5 +1,6 @@
 config BR2_PACKAGE_SSHGUARD
 	bool "sshguard"
+	depends on BR2_TOOLCHAIN_HAS_THREADS
 	select BR2_PACKAGE_IPTABLES # runtime
 	help
 	  sshguard protects hosts from brute-force attacks against SSH
@@ -8,3 +9,6 @@ config BR2_PACKAGE_SSHGUARD
 	  including iptables, ipfw, and pf.
 
 	  https://www.sshguard.net
+
+comment "sshguard needs a toolchain w/ threads"
+	depends on !BR2_TOOLCHAIN_HAS_THREADS