Fix down migration.

schemas/database/015_add_constraints_for_identities.down.sql

@@ -1,7 +1,7 @@
-DROP UNIQUE INDEX idx_unique_insertion_leaf;
-DROP UNIQUE INDEX idx_unique_deletion_leaf;
+DROP INDEX idx_unique_insertion_leaf;
+DROP INDEX idx_unique_deletion_leaf;
 
-DROP TRIGGER validate_pre_root_trigger;
+DROP TRIGGER validate_pre_root_trigger ON identities;
 DROP FUNCTION validate_pre_root();
 
 ALTER TABLE identities DROP COLUMN pre_root;

schemas/database/015_add_constraints_for_identities.up.sql

@@ -4,7 +4,7 @@ CREATE UNIQUE INDEX idx_unique_deletion_leaf on identities(leaf_index) WHERE com
 -- Add the new 'prev_root' column
 ALTER TABLE identities ADD COLUMN pre_root BYTEA;
 
--- This constraint ensures that we have consistent database and changes to the tre are done in a valid sequence.
+-- This constraint ensures that we have consistent database and changes to the tree are done in a valid sequence.
 CREATE OR REPLACE FUNCTION validate_pre_root() returns trigger as $$
     DECLARE
         last_id identities.id%type;