This was marked as BYTEA, but is more like TEXT, which is how we already
pass the history timeline file name.  Internally, we don't do any
encoding or bytea escape handling, but TEXT seems closest.  This should
cause no behavioral change.

Reported-by: Brar Piening

Discussion: https://postgr.es/m/6a1b9cd9-17e3-df67-be55-86102af6bdf5@gmx.de

Backpatch-through: master