tport_tls.c: removed global tls_ex_data_idx, using static one

Ignore-this: f13e52ca85d863d42ab6a2b2dd7afe02

darcs-hash:20090519170318-db55f-f748920bb0f9de38bf0f39873fd66bb8b64a5d97.gz

libsofia-sip-ua/tport/tport_tls.c

@@ -90,7 +90,7 @@ static int once;
 #include "tport_tls.h"
 
 char const tls_version[] = OPENSSL_VERSION_TEXT;
-int tls_ex_data_idx = -1; /* see SSL_get_ex_new_index(3ssl) */
+static int tls_ex_data_idx = -1; /* see SSL_get_ex_new_index(3ssl) */
 
 static void
 tls_init_once(void)