106_last_endpoint.t: ensure zmq_getsockopt(ZMQ_LAST_ENDPOINT) returns a string without trailing \0.
P5ZMQ3_zmq_getsockopt_string: remove trailing zero from ZMQ_LAST_ENDPOINT result.
Merge pull request #48 from mjg17/master

zmq_getsockopt for ZMQ_LAST_ENDPOINT should not return a string with a trailing null byte