[simple-scan] Use a better git source for libsane and lock it down to a release tag

[Robert Ancell <rancell src gnome org>]

commit d8ccda7381ffde6679bc1b7a1f6d42615650ab26
Author: Ken VanDine <ken vandine org>
Date:   Mon Aug 14 09:47:32 2017 -0400

    Use a better git source for libsane and lock it down to a release tag

 snap/snapcraft.yaml |    5 ++---
 1 files changed, 2 insertions(+), 3 deletions(-)
---
diff --git a/snap/snapcraft.yaml b/snap/snapcraft.yaml
index aeac0e1..f13f0b5 100644
--- a/snap/snapcraft.yaml
+++ b/snap/snapcraft.yaml
@@ -17,10 +17,9 @@ apps:
 parts:
   libsane:
     after: [desktop-gtk3]
-    source: https://github.com/kkaempf/sane-backends
+    source: https://anonscm.debian.org/cgit/sane/sane-backends.git
     source-type: git
-    source-branch: master
-    #source-tag: 3.24.0
+    source-tag: RELEASE_1_0_27
     plugin: autotools
     # workaround the issue described in https://launchpad.net/bugs/1583250
     configflags: [--prefix=/snap/simple-scan/current/usr, --with-api-spec=no]