logging - use self.print_error instead of util.print_error

lib/interface.py

@@ -144,7 +144,7 @@ class TcpConnection(threading.Thread, util.PrintError):
                     context = self.get_ssl_context(cert_reqs=ssl.CERT_REQUIRED, ca_certs=ca_path)
                     s = context.wrap_socket(s, do_handshake_on_connect=True)
                 except ssl.SSLError as e:
-                    print_error(e)
+                    self.print_error(e)
                     s = None
                 except:
                     return

lib/network.py

@@ -677,7 +677,7 @@ class Network(util.DaemonThread):
                     # check cached response for subscriptions
                     r = self.sub_cache.get(k)
                 if r is not None:
-                    util.print_error("cache hit", k)
+                    self.print_error("cache hit", k)
                     callback(r)
                 else:
                     message_id = self.queue_request(method, params)