set a default priority string if not set.

src/config.c

@@ -182,6 +182,9 @@ static void check_cfg( struct cfg_st *config)
 	
 	if (config->keepalive == 0)
 		config->keepalive = 30;
+	
+	if (config->priorities == NULL)
+		config->priorities = "NORMAL:%SERVER_PRECEDENCE:%COMPAT";
 }
 
 int cmd_parser (int argc, char **argv, struct cfg_st* config)

src/sample.config

@@ -33,7 +33,7 @@ server-key = /home/nmav/cvs/ocserv/test.pem
 #crl = /path/to/crl.pem
 
 # GnuTLS priority string
-tls-priorities = "PERFORMANCE:%SERVER_PRECEDENCE"
+tls-priorities = "PERFORMANCE:%SERVER_PRECEDENCE:%COMPAT"
 
 # The default server directory
 #chroot-dir = /root