core/advertising: Fix ManufaturerData dict type

The expect type for manufacturer ID is uint16_t not uint8_t.
diff --git a/src/advertising.c b/src/advertising.c
index d2019de..79b6042 100644
--- a/src/advertising.c
+++ b/src/advertising.c
@@ -302,7 +302,7 @@
 
 		dbus_message_iter_recurse(&entry, &value);
 
-		if (dbus_message_iter_get_arg_type(&value) != DBUS_TYPE_BYTE)
+		if (dbus_message_iter_get_arg_type(&value) != DBUS_TYPE_UINT16)
 			goto fail;
 
 		dbus_message_iter_get_fixed_array(&value, &manuf_data, &len);