obexd: Add property exist functions to map client
obexd: Add property exist functions to map client

This fixes crashes in MAP client when the server does not send optional properties.

0  0x00007ffff6a792c5 in raise () from /usr/lib/libc.so.6
1  0x00007ffff6a7a748 in abort () from /usr/lib/libc.so.6
2  0x00007ffff731c145 in ?? () from /usr/lib/libdbus-1.so.3
3  0x00007ffff7312a25 in ?? () from /usr/lib/libdbus-1.so.3
4  0x00007ffff73050d6 in dbus_message_iter_append_basic () from /usr/lib/libdbus-1.so.3
5  0x0000000000433cc5 in get_replyto (property=<optimized out>, iter=<optimized out>,
    data=<optimized out>) at obexd/client/map.c:484
6  0x00000000004103b6 in append_property (p=p@entry=0x6594c0 <map_msg_properties+192>,
    dict=dict@entry=0x7fffffffd8e0, iface=0x6a3720) at gdbus/object.c:547
7  0x0000000000410472 in append_properties (data=data@entry=0x6a3720, iter=iter@entry=
    0x7fffffffd960) at gdbus/object.c:576
8  0x00000000004104d1 in append_interface (data=0x6a3720, user_data=0x7fffffffda40)
    at gdbus/object.c:591
9  0x00007ffff7058a4d in g_slist_foreach () from /usr/lib/libglib-2.0.so.0
10 0x0000000000411d05 in emit_interfaces_added (data=0x6a2ff0) at gdbus/object.c:623
11 process_changes (user_data=0x6a2ff0) at gdbus/object.c:1006
12 0x00007ffff703c845 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
13 0x00007ffff703cb78 in ?? () from /usr/lib/libglib-2.0.so.0
14 0x00007ffff703cf72 in g_main_loop_run () from /usr/lib/libglib-2.0.so.0
15 0x000000000040df82 in main (argc=1, argv=0x7fffffffdd88) at obexd/src/main.c:323

silent-snowman/bluez,pstglia/external-bluetooth-bluez,mapfau/bluez,mapfau/bluez,pkarasev3/bluez,pstglia/external-bluetooth-bluez,mapfau/bluez,mapfau/bluez,pstglia/external-bluetooth-bluez,silent-snowman/bluez,ComputeCycles/bluez,silent-snowman/bluez,pkarasev3/bluez,pstglia/external-bluetooth-bluez,ComputeCycles/bluez,ComputeCycles/bluez,pkarasev3/bluez,silent-snowman/bluez,pkarasev3/bluez,ComputeCycles/bluez