Fixed conversion check

Author: tvincentNuoDB

pynuodb/encodedsession.py

@@ -445,7 +445,7 @@ def putOpaque(self, value):
         """Appends an Opaque data value to the message."""
         data = value.string
         length = len(data)
-        if systemVersion is '3' and type(value) is bytes:
+        if systemVersion is '3' and type(data) is bytes:
             data = data.decode('latin-1')
         if length < 40:
             packed = chr(protocol.OPAQUELEN0 + length) + data