Matt Harbison <matt_harbison@yahoo.com> [Fri, 01 Dec 2017 23:27:08 -0500] rev 35001
convert: restore the ability to use bzr < 2.6.0 (issue5733)
This effectively conditionalizes a234b32b744a. Some Linux distributions (like
CentOS 7) use really old versions, and the change referenced was causing
exceptions to be thrown.
Even though the deprecation warning says 'since 2.5.0', it wasn't marked as such
in 2.5.1, but is by 2.6.0. This was tested with 2.4.2 and 2.6.0 with
PYTHONWARNINGS=::DeprecationWarning, and both paths were exercized.