[seahorse] Accept GnuPG 2.2.x as supported version

[Rico Tzschichholz <ricotz src gnome org>]

commit 31a9a6ffc10f9737e70d7f0051ff590ff284ad07
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Tue Sep 5 00:01:16 2017 +0200

    Accept GnuPG 2.2.x as supported version

 configure.ac |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index fc4493c..723b46f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -9,7 +9,7 @@ GCR_REQUIRED=3.11.91
 GTK_REQ=3.4.0
 GTK_MAX=GTK_VERSION_3_4
 
-GNUPG_ACCEPTED="2.0.12 2.1.4"
+GNUPG_ACCEPTED="2.0.12 2.1.4 2.2.0"
 GPGME_REQUIRED=1.7.0
 LIBSECRET_REQUIRED=0.16
 AVAHI_GLIB_REQUIRED=0.6