Update Ghostgram features

Swiftgram/SGSharedAccountContextMigration/BUILD

@@ -0,0 +1,9 @@
+filegroup(
+    name = "SGSharedAccountContextMigration",
+    srcs = glob([
+        "Sources/**/*.swift",
+    ]),
+    visibility = [
+        "//visibility:public",
+    ],
+)

Swiftgram/SGSharedAccountContextMigration/Sources/SharedAccountContext+SGUISettingsMigration.swift

@@ -0,0 +1,19 @@
+// MARK: Swiftgram
+import SGLogging
+import SGAppGroupIdentifier
+import SGSimpleSettings
+import SwiftSignalKit
+import TelegramUIPreferences
+import AccountContext
+import Postbox
+import Foundation
+
+extension SharedAccountContextImpl {
+    // MARK: Swiftgram
+    func performSGUISettingsMigrationIfNecessary() {
+        if self.didPerformSGUISettingsMigration {
+            return
+        }
+        self.didPerformSGUISettingsMigration = true
+    }
+}