sugar.dispatch.dispatcher: remove fallback for Python 2.3
sugar.dispatch.dispatcher: remove fallback for Python 2.3

Other pieces of the code rely on Python 2.5, so there's no point in keeping
this. pep8 complained about lack of spacing in front of the inline comment,
so it needed touching anyway.

Reviewed-by: James Cameron <979be511e3d216882811a349af33a6d24f3f5f99@laptop.org>
Acked-by: Simon Schampijer <088e16a1019277b15d58faf0541e11910eb756f6@laptop.org>

ceibal-tatu/sugar-base,sugarlabs/sugar-base,sugarlabs/sugar-base,tchx84/debian-pkg-sugar-base,tchx84/debian-pkg-sugar-base,ceibal-tatu/sugar-base,tchx84/debian-pkg-sugar-base,ceibal-tatu/sugar-base,sugarlabs/sugar-base