Allow delay on renego on client

Currently unbounded: will be fixed later
diff --git a/library/ssl_cli.c b/library/ssl_cli.c
index d38d769..089b7c9 100644
--- a/library/ssl_cli.c
+++ b/library/ssl_cli.c
@@ -902,6 +902,12 @@
 
     if( ssl->in_msgtype != SSL_MSG_HANDSHAKE )
     {
+        if( ssl->renegotiation == SSL_RENEGOTIATION )
+        {
+            SSL_DEBUG_MSG( 1, ( "non-handshake message during renego" ) );
+            return( POLARSSL_ERR_SSL_WAITING_SERVER_HELLO_RENEGO );
+        }
+
         SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
         return( POLARSSL_ERR_SSL_UNEXPECTED_MESSAGE );
     }