[gnome-continuous] Bump up the libusb version

[Emmanuele Bassi <ebassi src gnome org>]

commit b1b03cea091f5641b8a277e23f20cac052ba723c
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Thu Apr 5 19:08:49 2018 +0100

    Bump up the libusb version
    
    Use 1.0.21, as that's what GVFS wants.

 manifest.json |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/manifest.json b/manifest.json
index faace2e..7d3565a 100644
--- a/manifest.json
+++ b/manifest.json
@@ -139,7 +139,7 @@
                  "tag-reason": "Vala-related build failure"},
 
                {"src": "git:https://github.com/libusb/libusb.git";,
-                "tag": "v1.0.19"},
+                "tag": "v1.0.21"},
 
                {"src": "git:git://github.com/gregkh/usbutils.git",
                 "patches": ["usbutils-autogen.patch"]},