build+sample_conf: option to print log call-site

sample-lnd.conf

@@ -978,12 +978,26 @@
 ; Don't add timestamps to logs written to stdout and stderr.
 ; logging.console.no-timestamps=false
 
+; Include the log call-site in the log line written to stdout
+; and stderr. Options include 'off', 'short' and 'long'.
+; Default:
+;   logging.console.call-site=off
+; Example:
+;   logging.console.call-site=short
+
 ; Disable logging to the standard LND log file.
 ; logging.file.disable=false
 
 ; Don't add timestamps to logs written to the standard LND log file.
 ; logging.file.no-timestamps=false
 
+; Include the log call-site in the log line written the standard LND
+; log file. Options include 'off', 'short' and 'long'.
+; Default:
+;   logging.file.call-site=off
+; Example:
+;   logging.file.call-site=short
+
 [watchtower]
 
 ; Enable integrated watchtower listening on :9911 by default.