Describe the bug
ttyd disconnects on browser connect if command is /bin/login from util-linux

To Reproduce
Steps to reproduce the behavior:

ttyd.x86_64 -p 8080 /bin/login

Expected behavior
ttyd should not disconnect

Environment:

• OS: CentOS/RHEL/RockyLinux/8
• ttyd.x86_64 1.6.3 static from release page
• util-linux 2.32.1-27.el8 from distro
• Browser: Version 93.0.4577.63 (Official Build) (64-bit)

Additional context

• /bin/login on console works
• command busybox login works under ttyd (busybox 1.31.0 static from busybox,net)