parseKeyStoreType crashes if type and wrap attributes not set

If both of the optional type and write attributes of a key store are not set in the configuration, parseKeyStoreType() raises a NullPointerException due to wrap being initialized as null, and then being checked in an if statement.

• Initialized on line 1847, crashes on line 2010 of ElytronXmlParser.java

The attached PR also fixes an issue where the KeyStore type detection code would not close a FileInputStream if it was successful.