Fix python3 problem with confetty

Under python3, there is no unicode.

confluent_client/bin/confetty

@@ -76,6 +76,11 @@ import confluent.termhandler as termhandler
 import confluent.tlvdata as tlvdata
 import confluent.client as client
 
+try:
+    unicode
+except NameError:
+    unicode = str
+
 conserversequence = '\x05c'  # ctrl-e, c
 clearpowermessage = False