python-bottle: bump version and fix shebang

Bump to version 0.11.6
Add the --executable shebang fixup option to the build phase so that the
script ends with a proper #!/usr/bin/python interpeter line set.

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>