package/libiscsi: needs threads

threads are needed since bump to version 1.19.0 and
https://github.com/sahlberg/libiscsi/commit/41af44eba113c59dc43764d1d240397616e85b82

Fixes:
 - http://autobuild.buildroot.org/results/1d71c95378a6ef9774926bf7431c1a315e4a1b3e

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Acked-by: Yann E. MORIN <yann.morin.1998@free.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/libiscsi/Config.in

@@ -1,5 +1,6 @@
 config BR2_PACKAGE_LIBISCSI
 	bool "libiscsi"
+	depends on BR2_TOOLCHAIN_HAS_THREADS
 	help
 	  Libiscsi is a client-side library to implement the iSCSI
 	  protocol that can be used to access resource of an iSCSI
@@ -10,3 +11,6 @@ config BR2_PACKAGE_LIBISCSI
 	  for simpler applications.
 
 	  https://github.com/sahlberg/libiscsi  (no proper homepage)
+
+comment "libiscsi needs a toolchain w/ threads"
+	depends on !BR2_TOOLCHAIN_HAS_THREADS