#461 ZipCrypto is still being used by default if available

[Yakov]

ZipCrypto is a very old, like 35 years old, and proven to be flawed as an encryption algorithm. Currently the code checks if ZipCrypto is available and if so selects it if AES-256 wasn't used last time. I propose the change to ensure that ZipCrypto isn't used by default unless used prior.

[Yakov]

The following code changes can be made:

--- a/CPP/7zip/UI/GUI/CompressDialog.cpp
+++ b/CPP/7zip/UI/GUI/CompressDialog.cpp
@@ -1742,8 +1742,8 @@ void CCompressDialog::SetEncryptionMethod()
     // if (ZipCryptoIsAllowed)
     {
       ComboBox_AddStringAscii(_encryptionMethod, "ZipCrypto");
-      sel = (encryptionMethod.IsPrefixedBy_Ascii_NoCase("aes") ? 1 : 0);
-      _default_encryptionMethod_Index = 0;
+      sel = (encryptionMethod.IsPrefixedBy_Ascii_NoCase("zipcrypto") ? 0 : 1);
+      _default_encryptionMethod_Index = 1;
     }
     ComboBox_AddStringAscii(_encryptionMethod, "AES-256");
     _encryptionMethod.SetCurSel(sel);