Fix caldav migration

app/src/main/java/org/tasks/db/Migrations.java

@@ -146,7 +146,7 @@ public class Migrations {
     private static final Migration MIGRATION_54_55 = new Migration(54, 55) {
         @Override
         public void migrate(@NonNull SupportSQLiteDatabase database) {
-            database.execSQL("CREATE TABLE IF NOT EXISTS `caldav_account` (`_id` INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL, `uuid` TEXT, `name` TEXT, `color` INTEGER NOT NULL, `deleted` INTEGER NOT NULL, `ctag` TEXT, `url` TEXT, `username` TEXT)");
+            database.execSQL("CREATE TABLE IF NOT EXISTS `caldav_account` (`_id` INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL, `uuid` TEXT, `name` TEXT, `color` INTEGER NOT NULL, `ctag` TEXT, `url` TEXT, `username` TEXT)");
             database.execSQL("CREATE TABLE IF NOT EXISTS `caldav_tasks` (`_id` INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL, `task` INTEGER NOT NULL, `account` TEXT, `remote_id` TEXT, `etag` TEXT, `last_sync` INTEGER NOT NULL, `deleted` INTEGER NOT NULL)");
         }
     };