Please apply attached patch and remove files/patch-configure.ac.

Also, I have got build error from pkg-fallout@FreeBSD.org on i386 13.0-CURRENT, but I could not reproduce it as I do not have i386 13.0-CURRENT. Please, do you know what to do?

...
--- tnftpd ---
/bin/sh ../libtool  --tag=CC    --mode=link cc  -O2 -pipe  -DSUPPORT_UTMPX -fstack-protector-strong -fno-strict-aliasing
+-fstack-protector-strong -o tnftpd cmds.o conf.o ftpd.o  ftpcmd.o popen.o logutmp.o  logwtmp.o
+../libnetbsd/libnetbsd.la  ../ls/libls.la -lpam -lcrypt
libtool: link: cc -O2 -pipe -DSUPPORT_UTMPX -fstack-protector-strong -fno-strict-aliasing -fstack-protector-strong -o
+tnftpd cmds.o conf.o ftpd.o ftpcmd.o popen.o logutmp.o logwtmp.o  ../libnetbsd/.libs/libnetbsd.a ../ls/.libs/libls.a
+-lpam -lcrypt
ld: error: duplicate symbol: __progname
>>> defined at ignore_init.c:83 (/usr/local/poudriere/jails/head-i386/usr/src/lib/csu/common/ignore_init.c:83)
>>>            /usr/lib/crt1.o:(__progname)
>>> defined at ftpd.c
>>>            ftpd.o:(.bss+0x8)
cc: error: linker command failed with exit code 1 (use -v to see invocation)
*** [tnftpd] Error code 1