Reset configuration before parsing users.conf.

Some values configured in chan_dahdi.conf were able to leak in to users.conf
configuration.  This was surprising users, and potentially setting non-sane
"defaults".

ASTNOW-125


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@303284 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_dahdi.c

@@ -12580,6 +12580,9 @@ static int setup_dahdi(int reload)
 	cfg = ast_config_load("users.conf");
 	if (cfg) {
 		char *cat;
+
+		/* Reset conf back to defaults, so values from chan_dahdi.conf don't leak in. */
+		conf = dahdi_chan_conf_default();
 		process_dahdi(&conf, "", ast_variable_browse(cfg, "general"), 1, 1);
 		for (cat = ast_category_browse(cfg, NULL); cat ; cat = ast_category_browse(cfg, cat)) {
 			if (!strcasecmp(cat, "general"))