Revert and improve commit 22e2b97, because …

 … I did not understand the logic / considerations for my own code any more

bin/sailfishos-chum-gui-installer

@@ -54,14 +54,15 @@ logfile="$2"
 umask 113
 [ "$PWD" = / ] || cd /  # Set PWD to /, if not already
 
-# Prefix first output with a linebreak, dashes and another linebreak, if logfile size > 0
+# Prefix first output with a line of underscores and an empty line, if logfile size > 0
+linebreaks=""
 if [ -s "$logfile" ]
-then printf '\n%s\n\n' "-----------------------------"
+then linebreaks='_____________________________\n\n'
 fi
 
 # Write first entry to logfile:
 logentry="[Info] PID $mypid is logging to $logfile on"
-if printf '%s %s\n' "$logentry" "$(date -Iseconds)"
+if printf "${linebreaks}%s\n" "$logentry $(date -Iseconds)"
 then systemd-cat -t "$called" -p 6 printf '%s\n' "$logentry"
 else systemd-cat -t "$called" -p 4 printf '%s\n' "[Warning] PID $mypid failed to write to $logfile"
 fi