FTBFS with gcc4.7

FTBFS with gcc4.7.
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gcc -DHAVE_CONFIG_H -I. -I.. -DPACKAGE_LOCALE_DIR=\""/usr/share/locale"\" -DPACKAGE_SRC_DIR=\""."\" -DPACKAGE_DATA_DIR=\""/usr/share"\" -DG_LOG_DOMAIN=\"WinWrangler\" -pthread -I/usr/include/pango-1.0 -I/usr/include/cairo -I/usr/include/startup-notification-1.0 -I/usr/include/glib-2.0 -I/usr/lib/x86_64-linux-gnu/glib-2.0/include -I/usr/include/gtk-2.0 -I/usr/include/pixman-1 -I/usr/include/freetype2 -I/usr/include/libpng12 -I/usr/lib/x86_64-linux-gnu/gtk-2.0/include -I/usr/include/atk-1.0 -I/usr/include/gdk-pixbuf-2.0 -I/usr/include/gio-unix-2.0/ -I/usr/include/gtkhotkey-1.0 -I/usr/include/libwnck-1.0 -D_FORTIFY_SOURCE=2 -Wall -g -g -O2 -fstack-protector --param=ssp-buffer-size=4 -Wformat -Werror=format-security -c main.c
main.c: In function ‘do_print_layouts’:
main.c:51:14: warning: assignment discards ‘const’ qualifier from pointer target type [enabled by default]
main.c: In function ‘do_bind_keys’:
main.c:63:10: warning: assignment discards ‘const’ qualifier from pointer target type [enabled by default]
main.c: In function ‘main’:
main.c:124:3: error: format not a string literal and no format arguments [-Werror=format-security]
main.c:75:17: warning: variable ‘tray_icon’ set but not used [-Wunused-but-set-variable]
cc1: some warnings being treated as errors

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