[gnome-software] Add support for "+" operator at the end of SPDX license identifiers

[Kalev Lember <klember src gnome org>]

commit c6c6691f5c373e84b05bc269afd786f779b4b4a2
Author: Kalev Lember <klember redhat com>
Date:   Sat Dec 31 16:34:00 2016 +0100

    Add support for "+" operator at the end of SPDX license identifiers
    
    Matching appstream-glib commit
    https://github.com/hughsie/appstream-glib/commit/ee450bd

 src/gs-shell-details.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/src/gs-shell-details.c b/src/gs-shell-details.c
index 91c205c..0c82105 100644
--- a/src/gs-shell-details.c
+++ b/src/gs-shell-details.c
@@ -1961,6 +1961,8 @@ gs_shell_details_license_free_cb (GtkWidget *widget, GsShellDetails *self)
                        continue;
                if (g_strcmp0 (tokens[i], "|") == 0)
                        continue;
+               if (g_strcmp0 (tokens[i], "+") == 0)
+                       continue;
 
                /* add widget */
                w = gs_shell_details_license_widget_for_token (self, tokens[i]);