fix error related with TruthValue
fix error related with TruthValue

The error was:
AttributeError: type object 'opencog.atomspace.TruthValue' has no attribute 'count_to_confidence'

See https://github.com/opencog/atomspace/pull/774

inflector/opencog,yantrabuddhi/opencog,ruiting/opencog,ruiting/opencog,AmeBel/opencog,AmeBel/opencog,yantrabuddhi/opencog,yantrabuddhi/opencog,misgeatgit/opencog,misgeatgit/opencog,ruiting/opencog,yantrabuddhi/opencog,misgeatgit/opencog,inflector/opencog,shujingke/opencog,shujingke/opencog,inflector/opencog,inflector/opencog,ruiting/opencog,misgeatgit/opencog,shujingke/opencog,andre-senna/opencog,shujingke/opencog,inflector/opencog,ruiting/opencog,misgeatgit/opencog,inflector/opencog,inflector/opencog,misgeatgit/opencog,AmeBel/opencog,inflector/opencog,AmeBel/opencog,andre-senna/opencog,yantrabuddhi/opencog,yantrabuddhi/opencog,yantrabuddhi/opencog,andre-senna/opencog,misgeatgit/opencog,AmeBel/opencog,misgeatgit/opencog,andre-senna/opencog,AmeBel/opencog,shujingke/opencog,andre-senna/opencog,AmeBel/opencog,shujingke/opencog,ruiting/opencog,andre-senna/opencog,ruiting/opencog,andre-senna/opencog,misgeatgit/opencog,shujingke/opencog