Drop the merged tables after conversion

Dependencies

• [2] HPEG2RHV Merge the BuildResultInfo table into the Builds table
• [*] MOX7XJ2E Merge the BuildSchedulingInfo table into the Builds table

Change contents

• edit in src/sql/upgrade-2.sql at line 42
  [2.12804]
  +

  + drop table BuildSchedulingInfo;

  + drop table BuildResultInfo;