mod_discord: Fix NULL dereference.

It seems that echochan can be NULL
even when echoguildid is set, so
add a NULL check before doing string
comparison.

Also remove unnecessary module self-ref/unref
from net_irc.

modules/mod_discord.c

@@ -705,7 +705,9 @@ static void fetch_channels(struct discord *client, u64snowflake guild_id, u64sno
 
 #ifdef RELAY_RCV_EVENTUALLY_FAILS
 		if (echoguildid && echoguildid == guild_id) {
-			if (!strcmp(echochan, channel->name)) {
+			if (strlen_zero(echochan)) {
+				bbs_warning("Echo guild ID is %lu but no echo channel parsed?\n", echoguildid);
+			} else if (!strcmp(echochan, channel->name)) {
 				echochanid = channel->id;
 				bbs_debug(1, "Channel %lu/%lu configured as echo channel\n", echoguildid, echochanid);
 			}

nets/net_irc.c

@@ -385,7 +385,6 @@ int irc_chanserv_register(void (*privmsg)(const char *username, char *msg), void
 		return -1;
 	}
 	/* This is the right order for these operations. Use reverse order for unregister. */
-	bbs_module_ref(BBS_MODULE_SELF, 2); /* Bump our module ref count */
 	chanserv_mod = mod;
 	chanserv_privmsg = privmsg;
 	chanserv_eventcb = eventcb;
@@ -401,7 +400,6 @@ int irc_chanserv_unregister(void (*privmsg)(const char *username, char *msg))
 	chanserv_privmsg = NULL;
 	chanserv_eventcb = NULL;
 	chanserv_mod = NULL;
-	bbs_module_unref(BBS_MODULE_SELF, 2);
 	return 0;
 }