sysutils/spiped: Update to 1.6.4

This fixes a bug which causes spiped to abort if a RST packet and a FIN
packet arrive from opposite ends of a pipe at the same time.

(cherry picked from commit a9635607)

sysutils/spiped/Makefile

 PORTNAME=	spiped
-PORTVERSION=	1.6.3
+PORTVERSION=	1.6.4
 CATEGORIES=	sysutils security
 MASTER_SITES=	http://www.tarsnap.com/spiped/
 

sysutils/spiped/distinfo

-TIMESTAMP = 1737846176
-SHA256 (spiped-1.6.3.tgz) = 70c53070dbbb10d1442754aeafb01b08ec829203d41023647dbf1a1435ee4a65
-SIZE (spiped-1.6.3.tgz) = 160649
+TIMESTAMP = 1743613766
+SHA256 (spiped-1.6.4.tgz) = 424fb4d3769d912b04de43d21cc32748cdfd3121c4f1d26d549992a54678e06a
+SIZE (spiped-1.6.4.tgz) = 158844