ssh client CHANGE explicitly allow all types for key exchange

Refs cesnet/netopeer2#499
diff --git a/src/session_client_ssh.c b/src/session_client_ssh.c
index 6bad75d..a36ea6f 100644
--- a/src/session_client_ssh.c
+++ b/src/session_client_ssh.c
@@ -1724,6 +1724,9 @@
     ssh_options_set(session->ti.libssh.session, SSH_OPTIONS_TIMEOUT, &timeout);
     ssh_options_set(session->ti.libssh.session, SSH_OPTIONS_HOSTKEYS, "ssh-ed25519,ecdsa-sha2-nistp256,"
             "ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,ssh-rsa,rsa-sha2-512,rsa-sha2-256,ssh-dss");
+    ssh_options_set(session->ti.libssh.session, SSH_OPTIONS_KEY_EXCHANGE, "curve25519-sha256,ecdh-sha2-nistp256,"
+            "diffie-hellman-group18-sha512,diffie-hellman-group16-sha512,diffie-hellman-group-exchange-sha256,"
+            "diffie-hellman-group14-sha1,diffie-hellman-group1-sha1,diffie-hellman-group-exchange-sha1");
 #ifdef HAVE_LIBSSH_OPTIONS_PUBLICKEY_ACCEPTED_TYPES
     ssh_options_set(session->ti.libssh.session, SSH_OPTIONS_PUBLICKEY_ACCEPTED_TYPES, "ssh-ed25519,ecdsa-sha2-nistp256,"
             "ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,ssh-rsa,rsa-sha2-512,rsa-sha2-256,ssh-dss");