tcptls: Avoid compiler warning on non-dev-mode.

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.8@420654 65c4cc65-6c06-0410-ace0-fbb531ad65f3

main/tcptls.c

@@ -434,7 +434,12 @@ static int tcptls_stream_close(void *cookie)
  */
 static void tcptls_stream_dtor(void *cookie)
 {
+#ifdef AST_DEVMODE
+	/* Since the ast_assert below is the only one using stream,
+	 * and ast_assert is only available with AST_DEVMODE, we
+	 * put this in a conditional to avoid compiler warnings. */
 	struct ast_tcptls_stream *stream = cookie;
+#endif
 
 	ast_assert(stream->fd == -1);
 }