legacy: fix import in bibstat cli

* Fixes import in bibstat script.  (closes #2293)

Signed-off-by: Jiri Kuncar <jiri.kuncar@cern.ch>
1: D100 Docstring missing
35: D400 First line should end with '.', not 't'
35: D205 Blank line missing between one-line summary and description
35: D208 Docstring is over-indented
43:14: E222 multiple spaces after operator
51: D200 One-line docstring should not occupy 3 lines
65: D200 One-line docstring should not occupy 3 lines
88: D200 One-line docstring should not occupy 3 lines
157:62: E502 the backslash is redundant between brackets
162: D200 One-line docstring should not occupy 3 lines
169:58: E128 continuation line under-indented for visual indent
170:58: E128 continuation line under-indented for visual indent
171:58: E128 continuation line under-indented for visual indent
175: D200 One-line docstring should not occupy 3 lines
184: D401 First line should be imperative: 'Print', not 'Prints'