BUG/MEDIUM: ssl: fix off-by-one in NPN list allocation

After seeing previous ALPN fix, I suspected that NPN code was wrong
as well, and indeed it was since ALPN was copied from it. This fix
must be backported into 1.6 and 1.5.
(cherry picked from commit 3724da126115d6ad0ccecbbcea05c54b4accaac4)
(cherry picked from commit 28cc8f12890a05934a99d7620b482896486b8a21)
1 file changed