[gnome-boxes] async-launcher: Ensure thread exit

[Zeeshan Ali <zeeshanak src gnome org>]

commit e476a02ab252513319d73e993f4f49dce58b9fc4
Author: Sebastien Nobert <sebastien nobert gmail com>
Date:   Mon Nov 21 16:04:44 2016 +0100

    async-launcher: Ensure thread exit

 src/async-launcher.vala |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/src/async-launcher.vala b/src/async-launcher.vala
index 57866d7..69122d4 100644
--- a/src/async-launcher.vala
+++ b/src/async-launcher.vala
@@ -37,6 +37,7 @@ public class Boxes.AsyncLauncher {
 
         yield;
 
+        thread.join();
         all_threads.remove (thread);
 
         if (e != null)