Limits quitting other AltStore processes to database migrations only

Previously, AltStore would quit all other processes when first accessing the database no matter what. However, this unintentionally caused the widget extension to quit the main app after refreshing apps.

Now, we only quit other AltStore processes if a database migration is required. This still prevents multiple AltStores with different database schemas from accessing database concurrently, but also allows extensions to access database without quitting main app.

AltStoreCore/Model/DatabaseManager.swift

@@ -53,7 +53,6 @@ public class DatabaseManager
     private let coordinatorQueue = OperationQueue()
     
     private var ignoreWillMigrateDatabaseNotification = false
-
     private init()
     {
         self.persistentContainer = PersistentContainer(name: "AltStore", bundle: Bundle(for: DatabaseManager.self))
@@ -93,7 +92,6 @@ public extension DatabaseManager
                 self.ignoreWillMigrateDatabaseNotification = true
                 CFNotificationCenterPostNotification(CFNotificationCenterGetDarwinNotifyCenter(), .willMigrateDatabase, nil, nil, true)
             }
-
             self.migrateDatabaseToAppGroupIfNeeded { (result) in
                 switch result
                 {