[gitg] Fix non-literal format string warnings

[Jesse van den Kieboom <jessevdk src gnome org>]

commit 444c3f3c0b1a604aed5a406f31d08eeb30f75f28
Author: Ting-Wei Lan <lantw src gnome org>
Date:   Wed Jul 27 12:28:17 2016 +0800

    Fix non-literal format string warnings
    
    https://bugzilla.gnome.org/show_bug.cgi?id=769209

 gitg/commit/gitg-commit.vala         |    2 +-
 gitg/gitg-author-details-dialog.vala |    1 +
 2 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/gitg/commit/gitg-commit.vala b/gitg/commit/gitg-commit.vala
index 10f9632..640a724 100644
--- a/gitg/commit/gitg-commit.vala
+++ b/gitg/commit/gitg-commit.vala
@@ -1312,7 +1312,7 @@ namespace GitgCommit
                private void on_discard_clicked()
                {
                        var primary = _("Discard changes");
-                       var secondary = _("Are you sure you want to permanently discard the selected 
changes?").printf();
+                       var secondary = _("Are you sure you want to permanently discard the selected 
changes?");
 
                        var q = new GitgExt.UserQuery();
 
diff --git a/gitg/gitg-author-details-dialog.vala b/gitg/gitg-author-details-dialog.vala
index 2a992f1..acb2c78 100644
--- a/gitg/gitg-author-details-dialog.vala
+++ b/gitg/gitg-author-details-dialog.vala
@@ -232,6 +232,7 @@ namespace Gitg
                                                                 Gtk.DialogFlags.DESTROY_WITH_PARENT,
                                                                 Gtk.MessageType.ERROR,
                                                                 Gtk.ButtonsType.OK,
+                                                                "%s",
                                                                 primary_message);
 
                        error_dialog.secondary_text = secondary_message;