[PATCH evolve-ext] directaccess: make sure gethashsymbols does not return rev numbers

[Jun Wu]

Excerpts from Laurent Charignon's message of 2016-06-22 21:55:13 +0100:
> We are doing the _ishashsymbol check multiple time per symbol (if
> len(tree>=3) because we know that gethashsymbols returned hashes symbols
> already.
> It is just duplicated work but it probably won't have any performance
> implication. What do you think?

Nice catch! V2 is coming.