user-accounts: Avoid markup in "Your Account" label

The label indicating which photo in the Carousel belongs to the
current user had the <small> markup within the translatable string,
causing unnecessary work for translators. See
https://wiki.gnome.org/TranslationProject/DevGuidelines/Avoid%20markup%20wherever%20possible

This patch formats the string with g_strdup_printf, leaving the
markup tags out of the translatable message.

panels/user-accounts/um-user-panel.c

@@ -192,7 +192,7 @@ create_carousel_entry (CcUserPanelPrivate *d, ActUser *user)
         g_free (label);
 
         if (act_user_get_uid (user) == getuid ())
-                label = g_strdup (_("<small>Your account</small>"));
+                label = g_strdup_printf ("<small>%s</small>", _("Your account"));
         else
                 label = g_strdup (" ");