[db] fix migration async execution issue

server/migrate.js

@@ -7,17 +7,3 @@ async function migrate() {
 }
 
 migrate();
-
-// temporary code for a non-sqlite migration:
-const normalise = s => s.trim().toLowerCase();
-
-async function populateUsernameNorm() {
-    const db = await dbConnection();
-    for ({id, username} of await db.all(`SELECT id, username FROM users WHERE usernameNorm IS NULL`)) {
-        const norm = normalise(username); // username is safe, so so will be norm
-        console.log(username, norm)
-        await db.all(`UPDATE users SET usernameNorm = '${norm}' WHERE id = '${id}'`);
-    }
-    await db.close();
-}
-populateUsernameNorm();