extensions: drop dead code trying to exclude deprecated disabled commands
Here 'ext' is a tuple, which means ext.__doc__ describes about the Python
tuple type. Fixing this would break 'hg help glog', which currently shows
some nice explanation, so this patch just removes the dead code.
$ hg help glog
'glog' is provided by the following extension:
graphlog command to view revision graphs from a shell (DEPRECATED)
(use 'hg help extensions' for information on enabling extensions)