restic 0.16.x changed the B2 URL format to use a colon between bucket and
path (b2:bucket:prefix) instead of a slash. The middlewared URL builder
produces b2:/bucket/path; restic then validates the full string after 'b2:'
as a bucket name, which fails because the slash is not in [a-z0-9-].
Fix the restic.py wrapper to strip the leading slash and replace the first
slash with a colon: b2:/bucket/path -> b2:bucket:path.
Also fix the hasattr bug in sitecustomize.py _patch_b2: hasattr() returns
True for methods inherited from the base class (which raises
NotImplementedError), causing the patch to be silently skipped. Use
'get_restic_config' not in cls.__dict__ instead.
flan
e8b0f961c7