[jcifs] empty strings in Config

[Life is hard, and then you die]

  Hi,

I was trying to set the jcifs.smb.client.domain and
jcifs.smb.client.username properties to the empty string, because that
makes far more sense than the "?\GUEST" that's used by default. However,
it turns out that jcifs.utils.PropertiesTree (line 356) will treat the
empty string as null and return null. Is there a good reason for this?
Or can the line be changed from 

		(  o instanceof String && ((String)o).length() > 0 )) {
to simply
		(  o instanceof String ) {


  Cheers,

  Ronald