Fixed boost.python detection in configure for older debian.
Fixed boost.python detection in configure for older debian.

svn path=/trunk/libavg/; revision=9129

yyd01245/libavg,scotty007/libavg,libavg/libavg,scotty007/libavg,libavg/libavg,th3infinity/libavg,yyd01245/libavg,hoodie/libavg,libavg/libavg,hoodie/libavg,yyd01245/libavg,th3infinity/libavg,yyd01245/libavg,th3infinity/libavg,hoodie/libavg,libavg/libavg,th3infinity/libavg,scotty007/libavg,hoodie/libavg,scotty007/libavg