sbservices: Read setIconState response

This allows the same connection to be used again after sbservices_set_icon_state is called.
Fixes #928.
diff --git a/src/sbservices.c b/src/sbservices.c
index ccb7c4b..c7ee911 100644
--- a/src/sbservices.c
+++ b/src/sbservices.c
@@ -172,7 +172,10 @@
 	if (res != SBSERVICES_E_SUCCESS) {
 		debug_info("could not send plist, error %d", res);
 	}
-	/* NO RESPONSE */
+
+	uint32_t bytes = 0;
+	service_receive_with_timeout(client->parent->parent, malloc(4), 4, &bytes, 2000);
+	debug_info("setIconState response: %u", bytes);
 
 	if (dict) {
 		plist_free(dict);