[epiphany] build: Fix build with clang -Werror and -Wwrite-strings

[Ting-Wei Lan <lantw src gnome org>]

commit 06152d563c07115f44535158656c2583d902b7d6
Author: Ting-Wei Lan <lantw src gnome org>
Date:   Tue Dec 15 03:13:02 2015 +0800

    build: Fix build with clang -Werror and -Wwrite-strings
    
    https://bugzilla.gnome.org/show_bug.cgi?id=759200

 src/ephy-encoding-dialog.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/src/ephy-encoding-dialog.c b/src/ephy-encoding-dialog.c
index 5ea7185..1d5d00e 100644
--- a/src/ephy-encoding-dialog.c
+++ b/src/ephy-encoding-dialog.c
@@ -44,7 +44,7 @@ struct _EphyEncodingDialog
        GtkWidget *enc_view;
        gboolean update_embed_tag;
        gboolean update_view_tag;
-       char *selected_encoding;
+       const char *selected_encoding;
 
        /* from the UI file */
        GtkStack *type_stack;