Fix migration that breaks Grenade jobs

Migration 33c3db036fe4_set_length_of_description_field_metering
needs to be changed as it is a reason of Grenade job's fail.

Closes-bug: #1307344

Change-Id: Ia57d9a60847e4a34977e40fb8b09181bdbd9c39b
Merge "Fix migration that breaks Grenade jobs"