Gajim with url-image-preview plugin (git master) hangs during closing.

05/30/2018 15:32:37 (I) nbxmpp.client_nb Disconnecting NBClient: 
05/30/2018 15:32:37 (D) nbxmpp.client_nb Client disconnected..
05/30/2018 15:32:37 (D) nbxmpp.client_nb Calling disconnect handler <bound method Connection.disconnectedReconnCB of <gajim.common.connection.Connection object at 0x7f529f97f978>>
05/30/2018 15:32:37 (I) gajim.c.connection disconnectedReconnCB called
^C^C
^CSIGINT/SIGTERM received
^CSIGINT/SIGTERM received
^CSIGINT/SIGTERM received
SIGINT/SIGTERM received
SIGINT/SIGTERM received
SIGINT/SIGTERM received
Killed

$ date
Wed May 30 19:05:55 CEST 2018

It was not even possible to interrupt Gajim with ctrl-c (SIGINT) or kill it with default SIGTERM. Only hard way with SIGKILL.

gdb shows Gajim waits for url image preview plugin to finish all its downloads. After ctrl-c Gajim's thread disappeared and only downloading thread remained hanging.

url-image-preview plugin should allow interruption when downloading. Gajim should interrupt downloads when quitting.

P.S. Does url-image-preview plugin support download resuming?