Minor change to gopher client example

examples/gopher.slo

@@ -74,7 +74,7 @@
 (define get-lines (lambda (link-line)
   (define conn (net-conn (get-line-host link-line) (get-line-port link-line) #f 10))
   (define output #f)
-  (if (not (exception? conn))
+  (if (and (not (exception? conn)) conn)
     (cond
       ;; If plain text, print it and add to history
       ;; Else, display error