use auto migration

app/src/main/java/com/github/libretube/db/AppDatabase.kt

@@ -1,5 +1,6 @@
 package com.github.libretube.db
 
+import androidx.room.AutoMigration
 import androidx.room.Database
 import androidx.room.RoomDatabase
 import com.github.libretube.db.dao.CustomInstanceDao
@@ -21,7 +22,10 @@ import com.github.libretube.db.obj.WatchPosition
         CustomInstance::class,
         LocalSubscription::class
     ],
-    version = 7
+    version = 7,
+    autoMigrations = [
+        AutoMigration(from = 7, to = 8)
+    ]
 )
 abstract class AppDatabase : RoomDatabase() {
     /**

app/src/main/java/com/github/libretube/db/DatabaseHolder.kt

@@ -13,7 +13,6 @@ object DatabaseHolder {
             AppDatabase::class.java,
             DATABASE_NAME
         )
-            .fallbackToDestructiveMigration()
             .build()
     }
 }