[Issue] Cant compress specific pdf

[bluntmess]

This pdf can't be compressed through this plugin - c4611_sample_explain.pdf

Receiving following errors:

W/System.err(18939): com.itextpdf.text.exceptions.BadPasswordException: PdfReader not opened with owner password
W/System.err(18939): at com.itextpdf.text.pdf.PdfStamperImp.(PdfStamperImp.java:168)
W/System.err(18939): at com.itextpdf.text.pdf.PdfStamper.(PdfStamper.java:98)
W/System.err(18939): at com.kaizen404.pdf_compressor.PdfCompressorPlugin$CompressPdf.saveCompressedPdfFromReader(PdfCompressorPlugin.java:83)
W/System.err(18939): at com.kaizen404.pdf_compressor.PdfCompressorPlugin$CompressPdf.run(PdfCompressorPlugin.java:78)
W/System.err(18939): at com.kaizen404.pdf_compressor.PdfCompressorPlugin.onMethodCall(PdfCompressorPlugin.java:43)
W/System.err(18939): at io.flutter.plugin.common.MethodChannel$IncomingMethodCallHandler.onMessage(MethodChannel.java:233)
W/System.err(18939): at io.flutter.embedding.engine.dart.DartMessenger.handleMessageFromDart(DartMessenger.java:85)
W/System.err(18939): at io.flutter.embedding.engine.FlutterJNI.handlePlatformMessage(FlutterJNI.java:818)
W/System.err(18939): at android.os.MessageQueue.nativePollOnce(Native Method)
W/System.err(18939): at android.os.MessageQueue.next(MessageQueue.java:335)
W/System.err(18939): at android.os.Looper.loop(Looper.java:183)
W/System.err(18939): at android.app.ActivityThread.main(ActivityThread.java:7656)
W/System.err(18939): at java.lang.reflect.Method.invoke(Native Method)
W/System.err(18939): at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
W/System.err(18939): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)