Fix exception after changing theme

app/src/main/java/com/kunzisoft/keepass/database/action/ProgressDialogThread.kt

@@ -199,7 +199,11 @@ class ProgressDialogThread(private val activity: FragmentActivity) {
 
         unBindService()
 
+        try {
             activity.unregisterReceiver(databaseTaskBroadcastReceiver)
+        } catch (e: IllegalArgumentException) {
+            // If receiver not register, do nothing
+        }
     }
 
     @Synchronized