Fix variable name

entrypoint.sh

@@ -31,7 +31,7 @@ fi
 
 # Overwrite the error code in case no links were found
 # and `fail-if-empty` is set to `true` (and it is by default)
-if [ "${INPUT_FAILIFEMPTY}" = true ]; then
+if [ "${INPUT_FAIL_IF_EMPTY}" = true ]; then
     # This is a somewhat crude way to check the Markdown output of lychee
     if echo "${LYCHEE_TMP}" | grep -E 'Total\s+\|\s+0'; then
         echo "No links were found. This usually indicates a configuration error." >> "${LYCHEE_TMP}"