fix(core): Updated upgrade file for remember me cookies for 1.9's new table.

Fixes #6629.
fix(session): fixes remember me functionality broken in 1.8.19 merge

Due to the change in how remember me hashes are stored in 1.9, we must
change the strategy a bit to handle multiple hashes. This also cleans up
the cookie read/write.
chore(upgrades): small SQL style improvement
Merge pull request #6632 from mrclay/brettp-updated_cookies_upgrade1

Fixes remember me upgrade and functionality
Merge github.com:Elgg/Elgg