folder.c:3949 Condition folder->klass->is_msg_changed != NULL failed
traceback:
0: /usr/bin/claws-mail(folder_item_is_msg_changed+0x151) [0x494531]
1: /usr/bin/claws-mail(procmsg_msg_exist+0x30) [0x55d120]
2: /usr/bin/claws-mail() [0x4674ac]
3: /usr/bin/claws-mail(compose_draft+0xcc0) [0x485b00]
4: /usr/bin/claws-mail() [0x485c49]
5: /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0(+0x4e573) [0x7ffff60d6573]
6: /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0(g_main_context_dispatch+0x158) [0x7ffff60d5ae8]
7: /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0(+0x4ded8) [0x7ffff60d5ed8]
8: /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0(g_main_loop_run+0xb2) [0x7ffff60d61d2]
9: /usr/lib/x86_64-linux-gnu/libgtk-x11-2.0.so.0(gtk_main+0xb7) [0x7ffff7a818e7]
10: /usr/bin/claws-mail(main+0xfc7) [0x449c37]
11: /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xe7) [0x7ffff5135b17]
12: /usr/bin/claws-mail(_start+0x2a) [0x44b41a]
