bpo-27122: Fix comment to point to correct issue number (#48)

It took me quite a bit to figure out what this was referring to,
since the given issue number is wrong, and the original commit
message I found through git blame lists a different, also wrong
issue number... see https://bugs.python.org/issue27122#msg279449

(cherry picked from commit af88e7eda4101f36e904771d3cf59a5f740b3b00)
1 file changed