Series 59d56a3fd7 introduced
an accidental backward incompatible regression by adding
a column to system_schema.keyspaces and then not even using
it for anything. It's a leftover from the original hackathon
implementation and should never reach master in the first place.
Fortunately, the series isn't part of any stable release yet.
Fixes#10376
Tests: manual, verifying that the system_schema.keyspaces table
no longer contains the extraneous column.
Closes#10377
fea18943cd