Allow TLSv1.1 and TLSv1.2.

This should in theory allow for later versions of TLS too but let's
verify that when the time comes.

tlscommon.c

@@ -208,7 +208,8 @@ static SSL_CTX *tlscreatectx(uint8_t type, struct tls *conf) {
     switch (type) {
 #ifdef RADPROT_TLS
     case RAD_TLS:
-	ctx = SSL_CTX_new(TLSv1_method());
+	ctx = SSL_CTX_new(SSLv23_method());
+        SSL_CTX_set_options(ctx, SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3);
 #ifdef DEBUG
 	SSL_CTX_set_info_callback(ctx, ssl_info_callback);
 #endif