KeepTableColumn still blocks on possible data loss

[j-dowsett]

Even though I have specified to keep a column, the publish still fails if the table has data in it ('Rows were detected. The schema update is terminating because data loss might occur'). To confirm I removed all data from the table, the publish went ahead, and my column was not dropped as intended. It would be helpful if the data loss check was not done if my filter specifies to not drop columns from a table.