When installing weboob in $HOME, the weboob base modules (weboob.browser...)
are installed in $HOME/.local/lib/python2.7/site-packages/... (see PEP-370).
When running weboob from the source directory with tools/local_run.sh, those
base modules are read from $HOME/.local instead of the source directory.
Passing the "-s" option to python makes it ignore $HOME/.local and read the
base modules from the source directory.
Signed-off-by: Matthieu Weber <mweber+weboob@free.fr>