Remove deprecated (in PHP 5.5) PREG /e modifier usage (#1489174)

CHANGELOG

@@ -1,6 +1,7 @@
 CHANGELOG Roundcube Webmail
 ===========================
 
+- Remove deprecated (in PHP 5.5) PREG /e modifier usage (#1489174)
 - Fix empty messages list when register_globals is enabled (#1489157)
 - Fix so valid and set date.timezone is not required by installer checks (#1489180)
 - Canonize boolean ini_get() results (#1489189)

installer/rcube_install.php

@@ -217,10 +217,12 @@ class rcube_install
       // save change
       $this->config[$prop] = $value;
 
+      $dump = self::_dump_var($value, $prop);
+
       // replace the matching line in config file
       $out = preg_replace(
-        '/(\$rcmail_config\[\''.preg_quote($prop).'\'\])\s+=\s+(.+);/Uie',
-        "'\\1 = ' . rcube_install::_dump_var(\$value, \$prop) . ';'",
+        '/(\$rcmail_config\[\''.preg_quote($prop).'\'\])\s+=\s+(.+);/Ui',
+        "\\1 = $dump;",
         $out);
     }