do not zero the address if not connected.  python depends on this.

Reference: /n/atom/patch/applied2013/getpeernz
Date: Thu Jun  6 20:07:46 CES 2013
Signed-off-by: quanstro@quanstro.net

--- /sys/src/ape/lib/bsd/getpeername.c	Thu Jun  6 20:07:12 2013
+++ /sys/src/ape/lib/bsd/getpeername.c	Thu Jun  6 20:07:12 2013
@@ -59,7 +59,7 @@
 
 	if(!connected(r, *alen)){
 		errno = ENOTCONN;
-		memset(&addr, 0, *alen);
+		/* memset(&addr, 0, *alen); python depends on this */
 		return -1;
 	}
 	return 0;