Fix yardoc for return type of #on_http_request

Author: rastating

lib/wpxf/net/http_server.rb

@@ -47,7 +47,7 @@ def http_server_bind_port
   #  to send to the client. If a hash is returned, it should contain the keys:
   #  * +:body+ - the body text of the response.
   #  * +:type+ - the MIME type of the response.
-  #  * +:headers+ - a hash of header keys and values.
+  #  * +:headers+ - an array of header strings.
   def on_http_request(path, params, headers)
   end