fix in db and collaborate

migrations/mysql/0028_collaboration_updates.sql

@@ -0,0 +1,11 @@
+ALTER TABLE note_revisions
+    ADD COLUMN collaboration_client_id VARCHAR(64) NULL,
+    ADD COLUMN collaboration_update_id BIGINT NULL,
+    ADD UNIQUE INDEX idx_note_revisions_collaboration_update
+        (note_id, collaboration_client_id, collaboration_update_id);
+
+ALTER TABLE revisions
+    ADD COLUMN collaboration_client_id VARCHAR(64) NULL,
+    ADD COLUMN collaboration_update_id BIGINT NULL,
+    ADD UNIQUE INDEX idx_revisions_collaboration_update
+        (pad_id, collaboration_client_id, collaboration_update_id);