package/proftpd: requires RMD160 support in openssl

Enable RMD160 in openssl to fix build failure raised since commit
a83d41867c8d69a77d5cd0a665aa216af5340359

Fixes:
 - http://autobuild.buildroot.org/results/4c3e7a77d8d6c326135fe467bfcae627df4a9b9b

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

package/proftpd/Config.in

@@ -29,6 +29,7 @@ config BR2_PACKAGE_PROFTPD_MOD_REDIS
 config BR2_PACKAGE_PROFTPD_MOD_SFTP
 	bool "mod_sftp support"
 	select BR2_PACKAGE_OPENSSL
+	select BR2_PACKAGE_LIBOPENSSL_ENABLE_RMD160 if BR2_PACKAGE_LIBOPENSSL
 	help
 	  Compile ProFTPD with mod_sftp support