Fix PHP 7.2 compatibility in debug_logger plugin (#6586)

CHANGELOG

@@ -4,6 +4,7 @@ CHANGELOG Roundcube Webmail
 - Fix bug where a message/rfc822 part without a filename wasn't listed on the attachments list (#6494)
 - Fix handling of empty entries in vCard import (#6564)
 - Fix bug in parsing some IMAP command responses that include unsolicited replies (#6577)
+- Fix PHP 7.2 compatibility in debug_logger plugin (#6586)
 
 RELEASE 1.3.8
 -------------

plugins/debug_logger/runlog/runlog.php

@@ -19,7 +19,7 @@ class runlog {
     public $timestamp        = "d-M-Y H:i:s O";
     public $max_line_size    = 150;
 
-    function runlog()
+    function __construct()
     {
         $this->start_time = microtime(true);
     }
@@ -71,9 +71,6 @@ class runlog {
             foreach ($this->tag_count as $tag => $count){
                 $tag_report .= "$tag: $count, ";
             }
-            if (!empty($tag_report)) {
-//                $tag_report = "\n$tag_report\n";
-            }
             $end_txt = sprintf("end: $name - %0.4f seconds $tag_report", $this->run_log[$lastk]['duration']);
             $this->print_to_console($end_txt, $this->run_log[$lastk]['tag'], 'end');
             $this->print_to_file($end_txt,  $this->run_log[$lastk]['tag'], 'end');
@@ -223,7 +220,6 @@ class runlog {
         return $buf;
     }
 
-
     function  __destruct()
     {
         foreach ($this->file_handles as $handle) {