[gnumeric] About: update copyright notice.

[Morten Welinder <mortenw src gnome org>]

commit ca605a01dc1e0c37198c0afa0aecbaed100bf584
Author: Morten Welinder <terra gnome org>
Date:   Sat Jun 27 13:36:06 2020 -0400

    About: update copyright notice.

 src/dialogs/dialog-about.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/dialogs/dialog-about.c b/src/dialogs/dialog-about.c
index bb3e2916b..3c97c67a9 100644
--- a/src/dialogs/dialog-about.c
+++ b/src/dialogs/dialog-about.c
@@ -589,7 +589,7 @@ dialog_about (WBCGtk *wbcg)
                          "website", PACKAGE_URL,
                          "website-label", _("Visit the Gnumeric website"),
                          "logo-icon-name", "gnumeric",
-                         "copyright", _("Copyright \xc2\xa9 1998-2018"),
+                         "copyright", _("Copyright \xc2\xa9 1998-2020"),
                          "comments", _("Free, Fast, Accurate - Pick Any Three!"),
                          "license", _(LICENSE_TEXT),
                          "wrap-license", TRUE,