lighttpd 1.4.50 config parse will error if include_shell exits non-zero
and pi-hole sample config: include_shell "cat external.conf 2>/dev/null"
is an error if external.conf does not exist
Replace with: include "external*.conf"
file glob supported since lighttpd 1.4.40 and is not an error if there
is no file which matches the file glob
Signed-off-by: Glenn Strauss <gstrauss@gluelogic.com>