imapx_command_fetch_message_done(): Avoid a refcount issue.
imapx_command_fetch_message_done(): Avoid a refcount issue.

Fix a potential reference counting issue, but I don't think this is
what's causing all the problems.

Distrotech/evolution-data-server,matzipan/evolution-data-server,matzipan/evolution-data-server,Distrotech/evolution-data-server,tintou/evolution-data-server,matzipan/evolution-data-server,matzipan/evolution-data-server,Distrotech/evolution-data-server,tintou/evolution-data-server,Distrotech/evolution-data-server,matzipan/evolution-data-server,Distrotech/evolution-data-server,tintou/evolution-data-server,tintou/evolution-data-server