resist crashing when given esp connections.  example

	minooka# cat /net/esp/1/local
	::

note lack of !port

	minooka# cat /net/esp/1/status
	Closed

strrchr(.., ' ') will fail on this string and \n messes
up output.

- erik

Reference: /n/sources/patch/applied/netstatesp
Date: Tue Apr 13 20:33:34 CES 2010
Signed-off-by: quanstro@quanstro.net

--- /sys/src/cmd/netstat.c	Tue Apr 13 20:31:26 2010
+++ /sys/src/cmd/netstat.c	Tue Apr 13 20:31:23 2010
@@ -147,7 +147,9 @@
 	p = strchr(buf, ' ');
 	if(p != 0)
 		*p = 0;
-	
+	p = strrchr(buf, '\n');
+	if(p != 0)
+		*p = 0;
 	Bprint(&out, "%-4s %-4s %-10s %-12s ", net, db->name, db->uid, buf);
 
 	sprint(buf, "%s/%s/%s/local", netroot, net, db->name);
@@ -185,7 +187,8 @@
 	buf[n-1] = 0;
 	close(fd);
 	p = strchr(buf, '!');
-	*p++ = '\0';
+	if(p != nil)
+		*p++ = '\0';
 
 	if(notrans){
 		Bprint(&out, "%-10s %s\n", getport(net, p), buf);