DOC: minor typo fixes to improve HTML parsing by haproxy-dconv

This must be backported to 1.6 and 1.5
(cherry picked from commit aa1ea8a9eef6ec2bc225cf303bfad8876cb8f887)
(cherry picked from commit 5fbd6f42f2d0923cff4dba0b4e8eda58570cd746)
1 file changed