looks like you're using minute resolution, so maybe:
data = btfeeds.GenericCSVData(
dataname="d_comma.csv",
nullvalue=0.0,
dtformat=('%d/%m/%Y %H:%M:%S'),
timeframe=bt.TimeFrame.Minutes,
datetime=0,
time=-1,
high=2,
low=3,
open=4,
close=5,
volume=6,
openinterest=-1
)