[libgsf] gsf: fix grammar in help text.

[Morten Welinder <mortenw src gnome org>]

commit f7d0442bc062a29e456e0d46038ced59855121dc
Author: Morten Welinder <terra gnome org>
Date:   Fri Mar 1 10:35:26 2013 -0500

    gsf: fix grammar in help text.

 tools/gsf.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/tools/gsf.c b/tools/gsf.c
index f8a1ce9..304cbd6 100644
--- a/tools/gsf.c
+++ b/tools/gsf.c
@@ -556,6 +556,6 @@ main (int argc, char **argv)
        if (strcmp (cmd, "createzip") == 0)
                return gsf_create (argc - 2, argv + 2, GSF_OUTFILE_TYPE_ZIP);
 
-       g_printerr (_("Run '%s help' to see a list subcommands.\n"), me);
+       g_printerr (_("Run '%s help' to see a list of subcommands.\n"), me);
        return 1;
 }