Remove PRNG seeding

This is done for the following reasons:
* Code clean-up. From https://secure.php.net/manual/en/function.mt-srand.php:
> Note: There is no need to seed the random number generator with srand() or mt_srand() as this is done automatically.

* Re-seeding of PRNGs makes them more predictable. E.g., the `microtime()` which is used for the seeding:
  * On Windows (before Win8): seems to return 0, according to https://stackoverflow.com/questions/18889244/php-5-5-on-windows-microtime-behavior.
  * On other OSes: The current time is easily guessable, with the "microseconds" part brute-forcible.

1 files changed, 0 insertions, 4 deletions

diff --git a/core/Common.php b/core/Common.php
index c6e0247941..7992275a56 100644
--- a/core/Common.php
+++ b/core/Common.php
@@ -584,10 +584,6 @@ class Common
         $chars = $alphabet;
         $str   = '';
 
-        list($usec, $sec) = explode(" ", microtime());
-        $seed = ((float)$sec + (float)$usec) * 100000;
-        mt_srand((int) $seed);
-
         for ($i = 0; $i < $length; $i++) {
             $rand_key = mt_rand(0, strlen($chars) - 1);
             $str .= substr($chars, $rand_key, 1);