Analyse broken pipe in response sending

[sfuhrm]

Fix non-critical broken pipe in TCP stream which shows with

curl -d DEBUG -X GET  http://localhost:54321/log4j2//level

Might be that this is linked to the extra HTTP body (-d DEBUG) sent.

NanoHTTPD$Response send
SCHWERWIEGEND: Could not send response to the client
java.net.SocketException: Datenübergabe unterbrochen (broken pipe) (Write failed)
	at java.net.SocketOutputStream.socketWrite0(Native Method)
	at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:111)
	at java.net.SocketOutputStream.write(SocketOutputStream.java:155)
	at fi.iki.elonen.NanoHTTPD$Response.sendBody(NanoHTTPD.java:1480)
	at fi.iki.elonen.NanoHTTPD$Response.sendBodyWithCorrectEncoding(NanoHTTPD.java:1453)
	at fi.iki.elonen.NanoHTTPD$Response.sendBodyWithCorrectTransferAndEncoding(NanoHTTPD.java:1443)
	at fi.iki.elonen.NanoHTTPD$Response.send(NanoHTTPD.java:1429)
	at fi.iki.elonen.NanoHTTPD$HTTPSession.execute(NanoHTTPD.java:871)
	at fi.iki.elonen.NanoHTTPD$ClientHandler.run(NanoHTTPD.java:189)
	at java.lang.Thread.run(Thread.java:748)

It's a little annoying that the error is displayed, but it's not a functional deficit.