removing a webseed torrent while it's running causes it to crash

[charles]

==22409== Thread 2:
==22409== Invalid read of size 4
==22409==    at 0x450761: readOrWritePiece (inout.c:190)
==22409==    by 0x450913: tr_ioWrite (inout.c:238)
==22409==    by 0x461692: webResponseFunc (webseed.c:234)
==22409==    by 0x44C59E: task_finish (web.c:180)
==22409==    by 0x44C65A: remove_finished_tasks (web.c:213)
==22409==    by 0x44C96C: tr_multi_socket_action (web.c:291)
==22409==    by 0x44CA3A: event_cb (web.c:326)
==22409==    by 0x46B4FE: event_base_loop (event.c:387)
==22409==    by 0x448F65: libeventThreadFunc (trevent.c:249)
==22409==    by 0x43E792: ThreadFunc (platform.c:123)
==22409==    by 0x363E0073D9: start_thread (in /lib64/libpthread-2.8.90.so)
==22409==    by 0x363D4E64FC: clone (in /lib64/libc-2.8.90.so)
==22409==  Address 0x4ff7264 is 148 bytes inside a block of size 1,128 free'd
==22409==    at 0x4A0609F: free (vg_replace_malloc.c:323)
==22409==    by 0x44A9EC: tr_free (utils.c:718)
==22409==    by 0x444DB8: freeTorrent (torrent.c:1109)
==22409==    by 0x44517A: closeTorrent (torrent.c:1246)
==22409==    by 0x448D81: readFromPipe (trevent.c:186)
==22409==    by 0x46B4FE: event_base_loop (event.c:387)
==22409==    by 0x448F65: libeventThreadFunc (trevent.c:249)
==22409==    by 0x43E792: ThreadFunc (platform.c:123)
==22409==    by 0x363E0073D9: start_thread (in /lib64/libpthread-2.8.90.so)
==22409==    by 0x363D4E64FC: clone (in /lib64/libc-2.8.90.so)

[charles]

fixed in r7078.