Bug 97113

Client crashes on second reboot of vm when webdav is enabled

version:
spice-gtk v0.32

Steps to reproduce:
1. connect to a vm with webdav
2. share a folder
3. restart vm two times

Actual result:
client crashes

Expected result:
no crash

Additional info:

 #0  0x00007ffff1662940 in g_task_return_error () at /lib64/libgio-2.0.so.0
 #1  0x00007ffff1662b60 in g_task_return_new_error () at /lib64/libgio-2.0.so.0
 #2  0x00007ffff57916e0 in read_cancelled (cancellable=<optimized out>, user_data=<optimized out>) at vmcstream.c:182
 #3  0x00007ffff1391555 in g_closure_invoke () at /lib64/libgobject-2.0.so.0
 #4  0x00007ffff13a4062 in signal_emit_unlocked_R () at /lib64/libgobject-2.0.so.0
 #5  0x00007ffff13acf5f in g_signal_emit_valist () at /lib64/libgobject-2.0.so.0
 #6  0x00007ffff13ad33f in g_signal_emit () at /lib64/libgobject-2.0.so.0
 #7  0x00007ffff16100d8 in g_cancellable_cancel () at /lib64/libgio-2.0.so.0
 #8  0x00007ffff5775c01 in port_event (self=0xc7af60, event=1) at channel-webdav.c:512
 #9  0x00007ffff1391555 in g_closure_invoke () at /lib64/libgobject-2.0.so.0
 #10 0x00007ffff13a445d in signal_emit_unlocked_R () at /lib64/libgobject-2.0.so.0
 #11 0x00007ffff13acf5f in g_signal_emit_valist () at /lib64/libgobject-2.0.so.0
 #12 0x00007ffff577479a in emit_main_context (opaque=0x7fffa5fff8d0) at gio-coroutine.c:200
 #13 0x00007ffff10b7847 in g_idle_dispatch () at /lib64/libglib-2.0.so.0
 #14 0x00007ffff10bade2 in g_main_context_dispatch () at /lib64/libglib-2.0.so.0
 #15 0x00007ffff10bb160 in g_main_context_iterate.isra () at /lib64/libglib-2.0.so.0
 #16 0x00007ffff10bb20c in g_main_context_iteration () at /lib64/libglib-2.0.so.0
 #17 0x00007ffff1677d2d in g_application_run () at /lib64/libgio-2.0.so.0
 #18 0x000000000041031a in main (argc=2, argv=0x7fffffffd928) at remote-viewer-main.c:42