fix: recreate smtp table with AUTOINCREMENT

[link2xt]

This ensures the rows cannot be confused accidentally when referred by row_id.

[r10s]

the missing rfc724_mid will cause problems on export -> import to a previous version - which is quite common, eg. there is always quite some time before all systems synchronize wrt new versions. if we do eg. an export from upcoming android 1.36.6 and import that to 1.36.5 , 1.36.5 will stop working as the INSERT INTO smtp will fail.

even if that is not nice, and the opportunity seems favorable, i suggest to keep the column. or use a new table so we can drop the old one at some later point.

apart from that, lgtm

[link2xt]

I restored rfc724_mid column, but without the index because it is not used anyway.

[r10s]

if rfc724_mid is not used otherwise (neither in older nor in newer versions), i think, the rfc724_mid can still be removed from INSERT INTO smtp (as in commits before) - as long as the column itself exist to be compatible with existing releases.
EDIT: after direct talk: filling rfc724_mid makes sense in case we use the column in the future.

otherwise, lgtm now