chan_gtalk: Fix potential use of uninitialized variable.

Avoid potential use of idroster in gtalk_alloc() before it has been
initialized.


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.8@359508 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_gtalk.c

@@ -979,7 +979,7 @@ static struct gtalk_pvt *gtalk_alloc(struct gtalk *client, const char *us, const
 	struct gtalk_pvt *tmp = NULL;
 	struct aji_resource *resources = NULL;
 	struct aji_buddy *buddy = NULL;
-	char idroster[200];
+	char idroster[200] = "";
 	char *data, *exten = NULL;
 	struct ast_sockaddr bindaddr_tmp;