[tracker] Correct typo in comment

[Sam Thursfield <sthursfield src gnome org>]

commit 279c59edbb6c40e4d8a93592e0b0a5e011f1e94c
Author: Sam Thursfield <sam afuera me uk>
Date:   Sun Jul 27 15:00:39 2014 +0200

    Correct typo in comment

 src/tracker-writeback/tracker-main.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/src/tracker-writeback/tracker-main.c b/src/tracker-writeback/tracker-main.c
index 6e77710..e944540 100644
--- a/src/tracker-writeback/tracker-main.c
+++ b/src/tracker-writeback/tracker-main.c
@@ -92,7 +92,7 @@ main (int   argc,
        bind_textdomain_codeset (GETTEXT_PACKAGE, "UTF-8");
        textdomain (GETTEXT_PACKAGE);
 
-       /* Translators: this messagge will apper immediately after the
+       /* Translators: this message will appear immediately after the
         * usage string - Usage: COMMAND <THIS_MESSAGE>
         */
        context = g_option_context_new (_("- start the tracker writeback service"));