Python detection fallout with non GNU sed

[Joel Brobecker]

> a recent commit to the configure.ac/configure in src/gdb broke the
> machinery on machines which do not have GNU sed.

That's me, sorry.

> I tried the follwoing on those systems and on linux-ppc:
> 
> sed -e 's,^.* -l\(python[0-9]*[.][0-9]*\).*$,\1,'`
> 
> (the same expression w/o the \? quantifier.)

This is not going to work on Windows, because windows the python
library does not have the dot in the version number (Eg: Python27).

I've checked in a fix.  Can you retry?

-- 
Joel