obexd/bluetooth: Fix memory leak when adapter is off

obexd/bluetooth: Fix memory leak when adapter is off

sdp_connect fails when Bluetooth adapter is off which leads to the
following leak:
37 bytes in 1 blocks are definitely lost in loss record 68 of 165
   at 0x4A06409: malloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
   by 0x3B03C4D89E: g_malloc (in /usr/lib64/libglib-2.0.so.0.3600.3)
   by 0x3B03C64BAE: g_strdup (in /usr/lib64/libglib-2.0.so.0.3600.3)
   by 0x427D5D: bluetooth_connect (bluetooth.c:410)
   by 0x426CC9: obc_session_create (session.c:454)
   by 0x425693: create_session (manager.c:203)
   by 0x43D8A3: process_message.isra.5 (object.c:259)
   by 0x3B0701CE85: ??? (in /usr/lib64/libdbus-1.so.3.7.4)
   by 0x3B0700FA30: dbus_connection_dispatch (in /usr/lib64/libdbus-1.so.3.7.4)
   by 0x43A627: message_dispatch (mainloop.c:76)
   by 0x3B03C48962: ??? (in /usr/lib64/libglib-2.0.so.0.3600.3)
   by 0x3B03C47E05: g_main_context_dispatch (in /usr/lib64/libglib-2.0.so.0.3600.3)