initerrors(): Eliminate circular reference which was causing a small

initerrors(): Eliminate circular reference which was causing a small
but annoying memory leak.  This was introduced when PyExc_Exception
was added; the loop above populating the PyExc_StandardError exception
tuple started at index 1 in bltin_exc, but PyExc_Exception was added
at index 0, so PyExc_StandardError was getting inserted in itself!
How else can a tuple include itself?!

Change the loop to start at index 2.

This was a *fun* one! :-)