framework: update checkout.

Submodule framework ba54771..87bf533:
> scripts/shell.utils: stage_lister_directory: do not inherit stage lister for
subsession calls on directories.
> scripts/urlops: add functions for URL escaping operations (rawurlencode and
rawurldecode).
> scripts/shell: improve debug (use single quotes).
> scripts/shell: runner: (hopefully) improve error handling of the invoked
command.
> scripts/shell: drop selective stage list.
> scripts/shell.utils: stage_lister_directory: fix quoting in call of
subsession runner.
> scripts/parser: build_cstyle_call: escape parentheses.
> scripts/parser: parse_cstyle_call: fix escaping in case of no argument.