after I uninstalled the package bash, I can not log in via ssh any more. The GUI still works, but I get no shell:
~$ ssh openwrt root@openwrt: Permission denied (publickey).
As soon as I re-install bash, ssh works again. Tests showed that after uninstalling bash, /etc/passwd still points to /bin/bash as root's shell:
But even after manually changing this to /bin/sh/ no logging in is possible. So there must be some place where ssh is installed to use /bin/bash instead of /bin/sh.