libssh2: security bump to version 1.5.0

Fixes CVE-2015-1782 - kex: bail out on rubbish in the incoming packet.

Also add hash file.

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/libssh2/libssh2.hash

@@ -0,0 +1,2 @@
+# Locally calculated after checking pgp signature
+sha256	83196badd6868f5b926bdac8017a6f90fb8a90b16652d3bf02df0330d573d0fc	libssh2-1.5.0.tar.gz

package/libssh2/libssh2.mk

@@ -4,7 +4,7 @@
 #
 ################################################################################
 
-LIBSSH2_VERSION = 1.4.3
+LIBSSH2_VERSION = 1.5.0
 LIBSSH2_SITE = http://www.libssh2.org/download
 LIBSSH2_LICENSE = BSD
 LIBSSH2_LICENSE_FILES = COPYING