migrations: add constraint for kanjidic skip misclassifications

migrations/0006_KANJIDIC2.sql

@@ -113,6 +113,7 @@ CREATE TABLE "KANJIDIC_QueryCode" (
   "code" VARCHAR(7) NOT NULL,
   "type" VARCHAR(11) NOT NULL CHECK ("type" IN ('skip', 'sh_desc', 'four_corner', 'deroo', 'misclass')),
   "SKIPMisclassification" VARCHAR(15),
+  CHECK ("SKIPMisclassification" IS NULL OR "type" = 'skip'),
   PRIMARY KEY ("kanji", "type", "code")
 ) WITHOUT ROWID;