mail_hash_rebuild() now tries to lock itself, fixing crash if trying to rebuild hash when opening index
mail_hash_rebuild() now tries to lock itself, fixing crash if trying to
rebuild hash when opening index

--HG--
branch : HEAD

jwm/dovecot-notmuch,dscho/dovecot,dscho/dovecot,jkerihuel/dovecot,jwm/dovecot-notmuch,jkerihuel/dovecot,jkerihuel/dovecot,jkerihuel/dovecot,dscho/dovecot,jwm/dovecot-notmuch,dscho/dovecot,dscho/dovecot,jwm/dovecot-notmuch,jwm/dovecot-notmuch,jkerihuel/dovecot