fix: allow to use password encrypted keys

[kuisathaverat]

see JENKINS-63601

java.lang.IllegalArgumentException: java.security.NoSuchAlgorithmException: Cannot find any provider supporting PBEWithMD5AndDESede
	at com.trilead.ssh2.crypto.cipher.JreCipherWrapper.getInstance(JreCipherWrapper.java:26)
	at com.trilead.ssh2.crypto.cipher.JreCipherWrapperTest.testPBEWithMD5AndDESede(JreCipherWrapperTest.java:60)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

testSupportedCiphersAvailable(com.trilead.ssh2.crypto.cipher.JreCipherWrapperTest)  Time elapsed: 0.107 sec  <<< ERROR!
java.lang.IllegalArgumentException: java.security.NoSuchAlgorithmException: Cannot find any provider supporting PBEWithMD5AndAES_128
	at com.trilead.ssh2.crypto.cipher.JreCipherWrapper.getInstance(JreCipherWrapper.java:26)
	at com.trilead.ssh2.crypto.cipher.JreCipherWrapperTest.testSupportedCiphersAvailable(JreCipherWrapperTest.java:62)

regression #45

[MarkEWaite]

I confirmed that PBEWithMD5AndTripleDES is mentioned in https://docs.oracle.com/javase/7/docs/technotes/guides/security/SunProviders.html and in other articles and that PBEWithMD5AndDESede is mentioned elsewhere but is not mentioned in the Oracle docs.

[jvz]

It's bad enough that 3DES is still in use (it's incredibly slow compared to pretty much any other symmetric cipher; it might still be secure); I remember coming across this problem back when I was working on it. Depending on which JCA providers you have installed, 3DES has two different names apparently.

[jvz]

Nit: is there a @SuppressWarnings of some sort to apply here? Any sort of static code scanner will end up crying about MD5 usage despite it being valid here.