Prior to 2f4e8dc3e8 we would take
the written ToxID and insert that straight into history without
any case check
Must be done prior to schema 11 since even though the UNIQUE constraint
on the peers table is fooled by the different case, the UNIQUE
constraint on the new chats and authors table which are stored as BLOBS
fail during upgrade when the two different case but equal ToxPks
collide.
Unfortunately it can't be done as its own upgrade since 11 was already
merged, and this is a prerequisite for 11 to pass for some users.
Execute prior to starting the split peer upgrade instead of as a larger
transaction for simplicity of the split upgrade, and since executing
this deduplication is idempotent.
9a8706a65f