Fix emitting UUIDs signals when initializing adapters

Drivers get loaded while adapters get initialized, but we shouldn't send
any UUID signals before the initialization is fully complete (otherwise
we get adapter signals before the Manager.AdapterAdded signals).
diff --git a/src/adapter.c b/src/adapter.c
index 5894146..1d6eef5 100644
--- a/src/adapter.c
+++ b/src/adapter.c
@@ -1025,6 +1025,9 @@
 	int i;
 	sdp_list_t *list;
 
+	if (!adapter->initialized)
+		return;
+
 	uuids = g_new0(char *, sdp_list_len(adapter->services) + 1);
 
 	for (i = 0, list = adapter->services; list; list = list->next) {