Simplify, supress output

src/adapt-user.sh

@@ -19,13 +19,8 @@ main() {
     # Add user to tty group for /dev/pts/* access
     addgroup "${username}" tty 2>/dev/null
 
-    if tty -s; then
+    if [ -c "/dev/pts/0" ]; then
-        local tty_device
+        chmod g+rw "/dev/pts/0" 2>/dev/null
-        tty_device="$(tty)"
-
-        if [ -f "${tty_device}" ]; then
-            chmod g+rw "${tty_device}" 2>/dev/null
-        fi
     fi
 }
 main "${@}"