Correct the credential privilege XPath (don't include the root node).

This is a bug fix for yesterday's buggy bug fix.

protogeni/lib/GeniCredential.pm.in

@@ -519,7 +519,7 @@ sub CreateFromSigned($$;$)
     bless($self, $class);
 
     # Dig out the capabilities
-    foreach my $cap (GeniXML::FindNodes('n:signed-credential/n:credential/' .
+    foreach my $cap (GeniXML::FindNodes('n:credential/' .
 					'n:privileges/n:privilege',
 					$root)->get_nodelist()) {
 	my $name = GeniXML::FindElement('n:name', $cap);