package/s390-tools: properly fix build with libcurl

Update third patch to fix the following build failure:

/bin/sh: 1: curl-config: not found
make[2]: Leaving directory '/tmp/instance-2/output-1/build/s390-tools-2.17.0/libvmdump'
Error: libcurl is not built with the OpenSSL backend
make[2]: *** [Makefile:54: check-dep-libekmfweb] Error 1

Fixes:
 - http://autobuild.buildroot.org/results/b4ebe39e54f80b26bc81b249bfa643140c41d0bd



Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>