Code review comment for lp:~kalikiana/midori/appprivacy

There is an issue with the "app" object (if you change some settings):

** (midori4:3734): CRITICAL **: katze_object_get_object: assertion `G_IS_OBJECT (object)' failed

Program received signal SIGTRAP, Trace/breakpoint trap.
0x00007ffff78dcd4d in g_logv () from /usr/lib/libglib-2.0.so.0
(gdb) bt
#0 0x00007ffff78dcd4d in g_logv () from /usr/lib/libglib-2.0.so.0
#1 0x00007ffff78dcf32 in g_log () from /usr/lib/libglib-2.0.so.0
#2 0x000000000042a50a in katze_object_get_object (object=object@entry=0x0, property=property@entry=0x482f2c "extensions") at ../katze/katze-utils.c:1209
#3 0x00000000004596b2 in midori_settings_save_to_file (settings=settings@entry=0x862b10, app=0x0, filename=filename@entry=0x1076440 "/home/andre/.local/share/midori/apps/0d31a7f58f9a80b737cb713872090cc6/config",
    error=error@entry=0x7fffffffcbb8) at ../midori/midori-websettings.c:1486
#4 0x000000000044c86d in settings_notify_cb (settings=0x862b10, pspec=<optimized out>, app=0x0) at ../midori/midori-session.c:353