fix: fix up pathname expansions (fixup 89dc92e)

Author: akinomyoga

bash_completion

@@ -1133,6 +1133,7 @@ _configured_interfaces()
     if [[ -f /etc/debian_version ]]; then
         # Debian system
         _comp_expand_glob files '/etc/network/interfaces /etc/network/interfaces.d/*'
+        ((${#files[@]})) || return 0
         COMPREPLY=($(compgen -W "$(command sed -ne 's|^iface \([^ ]\{1,\}\).*$|\1|p' \
             "${files[@]}" 2>/dev/null)" \
             -- "$cur"))