BUILD/MINOR: ssl: shut up a build warning about format truncation

Actually gcc believes it has detected a possible truncation but it
cannot since the output string is necessarily at least one char
shorter than what it expects. However addressing it is easy and
removes the need for an intermediate copy so let's do it.

(cherry picked from commit 0580052bb6f9c924daedfe62d779eade68677adf)
Signed-off-by: Willy Tarreau <w@1wt.eu>
1 file changed