debug/ltrace: pump ltrace to version 0.7.3

pump ltrace to version 0.7.3
backport a patch from Peter Wu to silence warnings/errors in ltrace

Signed-off-by: '"Peter Wu" <lekensteyn@gmail.com>'
Signed-off-by: '"Daniel Zimmermann" <netzimme@gmail.com>'
[yann.morin.1998@free.fr: remove superfluous empty lines]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Message-Id: <8349c35b506aa79c4e69.1392845765@haus-VirtualBox>
Patchwork-Id: 322017

python

import sys

sys.path.insert(0, '@@PREFIX@@/share/gcc-@@VERSION@@/python')

from libstdcxx.v6.printers import register_libstdcxx_printers

register_libstdcxx_printers (None)

end