I had to make this modification locally to get opencv to build with python 2.6.  Python 2.6 requires indices in the format string (the `0` I added).  This requirement was relaxed in 2.7, so what used to be there would be working for people who could upgrade. I don't think the change has any negative consequences for future python versions, but I'm no expert.

This silences the pedantic warning messages from gcc 4.8.3

(performance) Possible inefficient checking for 'lmap' emptiness
(warning) Assignment of function parameter has no effect outside the function. Did you forget dereferencing it?
(style) Array index '<xxx>' is used before limits check