fixed typo, "header" ==> "headers"

Doc/lib/libhttplib.tex

@@ -94,7 +94,7 @@ read the reply from the server, and return a triple (\var{replycode},
 \var{message}, \var{headers}).  Here \var{replycode} is the integer
 reply code from the request (e.g.\ \code{200} if the request was
 handled properly); \var{message} is the message string corresponding
-to the reply code; and \var{header} is an instance of the class
+to the reply code; and \var{headers} is an instance of the class
 \code{mimetools.Message} containing the headers received from the server.
 See the description of the \code{mimetools} module.
 \stmodindex{mimetools}

Doc/libhttplib.tex

@@ -94,7 +94,7 @@ read the reply from the server, and return a triple (\var{replycode},
 \var{message}, \var{headers}).  Here \var{replycode} is the integer
 reply code from the request (e.g.\ \code{200} if the request was
 handled properly); \var{message} is the message string corresponding
-to the reply code; and \var{header} is an instance of the class
+to the reply code; and \var{headers} is an instance of the class
 \code{mimetools.Message} containing the headers received from the server.
 See the description of the \code{mimetools} module.
 \stmodindex{mimetools}