[glibmm] ustring: Don't say "message string" for sprintf()

[Daniel Boles <dboles src gnome org>]

commit 98419b8a9bc9173c3c95f7e02c25da7263b940e5
Author: Daniel Boles <dboles src gnome org>
Date:   Fri Jun 21 18:57:38 2019 +0100

    ustring: Don't say "message string" for sprintf()
    
    I just copied that from compose() and am not sure of its precise
    intended meaning, but in case it conveys 'a string suitable for showing
    a message, i.e. a translatable string', let's not give that incorrect
    impression, since placeholders can't be reordered by translators. See
    also https://gitlab.gnome.org/GNOME/glibmm/issues/21#note_533829 et al.

 glib/glibmm/ustring.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/glib/glibmm/ustring.h b/glib/glibmm/ustring.h
index 4fe58aff..1d62b1e0 100644
--- a/glib/glibmm/ustring.h
+++ b/glib/glibmm/ustring.h
@@ -757,7 +757,7 @@ public:
    * @param fmt The template string, in the format used by <tt>printf()</tt> et al.
    * @param args A set of arguments having the number and types required by @a fmt.
    *
-   * @return The substituted message string.
+   * @return The substituted string.
    *
    * @newin{2,62}
    */