Fix bug where NETFARM:PARSE-BLOCK would loop indefinitely
Calling netfarm:parse-block
like
(defclass foo-class ()
((a :initarg :a)
(b :initarg :b)
(c :initarg :c))
(:metaclass netfarm:netfarm-class))
(netfarm:parse-block
(netfarm:render-object
(make-instance 'foo-class
:a 3
:b 3)))
would cause the system to loop forever. This can be reconstructed with the test case I created
(let ((netfarm::*in-slot?* t))
(netfarm::parse-all "~"))