Explain request length

Signed-off-by: Lorenzo Fontana <lo@linux.com>

Author: fntlnz

README.md

@@ -16,7 +16,7 @@ every request to an InfluxDB backend exposing UDP.
 | uri                   | string  | The called uri (e.g: /index.html)                                                                                                                                                                     |
 | extension             | string  | The extension of the served file (e.g: js, html, php, png)                                                                                                                                            |
 | content_type          | string  | The content type of the response (e.g: text/html)                                                                                                                                                     |
-| request_time          | string  | Request processing time in seconds with a milliseconds resolution; time elapsed between the first bytes were read from the client and the log write after the last bytes were sent to the client      |
+| request_time          | string  | Request processing time in seconds with a milliseconds resolution                                                                                                                                     |
 
 
 ## Installation