Fix constraints on waterway profiles staging_done in the UNIQUE constraint had no effect, because the exclusion constraint prevented two rows with equal location and validity anyhow. Adding staging_done to the exclusion constraint makes the UNIQUE constraint checking only a corner case of what the exclusion constraint checks. Thus, remove the UNIQUE constraint. Casting staging_done to int is needed because there is no appropriate operator class for booleans. Casting to smallint or even bit would have been better (i.e. should result in smaller index size), but that would have required creating such a CAST, in addition.

teichmann@intevation.de = sascha.teichmann@intevation.de
bernhard.reiter@intevation.de = bernhard@intevation.de