[ostree] gpg-sign: Update man page for --delete option

[Matthew Barnes <mbarnes src gnome org>]

commit bf69c4b44a988ce4e3fe54761fcb75946d0879f1
Author: Matthew Barnes <mbarnes redhat com>
Date:   Fri Mar 20 12:57:20 2015 -0400

    gpg-sign: Update man page for --delete option

 doc/ostree-gpg-sign.xml |    8 ++++++++
 1 files changed, 8 insertions(+), 0 deletions(-)
---
diff --git a/doc/ostree-gpg-sign.xml b/doc/ostree-gpg-sign.xml
index 0c7ab7d..44ddb65 100644
--- a/doc/ostree-gpg-sign.xml
+++ b/doc/ostree-gpg-sign.xml
@@ -69,6 +69,14 @@ Boston, MA 02111-1307, USA.
 
         <variablelist>
             <varlistentry>
+                <term><option>--delete</option></term>
+
+                <listitem><para>
+                    Delete signatures having any of the GPG KEY-IDs.
+                </para></listitem>
+            </varlistentry>
+
+            <varlistentry>
                 <term><option>--gpg-homedir</option>="HOMEDIR"</term>
 
                 <listitem><para>