Description of problem:
When running e.g. phpMyAdmin 4.4.14 on RHEL 6 this causes a warning:

  openssl_encrypt(): Using an empty Initialization Vector (iv) is potentially 
    insecure and not recommended

This however is not a bug in phpMyAdmin, but in PHP 5.3.3 as shipped by
RHEL 6 and is already fixed at upstream.

Finally, something like

  openssl_encrypt(str_repeat('.', 16), 'aes-256-ecb', str_repeat('a', 32), 
    true);

causes the warning while ECB mode doesn't make use of an IV.

Note: This requires phpMyAdmin 4.4.x as shipped by upstream, not the EPEL
package (which is 4.0.x due to the old MySQL version in RHEL 6). And this
also requires a MariaDB (either via SCL or remote).

Version-Release number of selected component (if applicable):
php-5.3.3-46.el6_6

How reproducible:
Everytime, see above and below.

Actual results:
Wrong warning of openssl_encrypt() for missing IV even IV is not required.

Expected results:
No warning.

Additional info:
- https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=613815
- http://git.php.net/?p=php-src.git;a=commitdiff;h=412d15168192fdd3afafca5cff034bb5b451942f
- http://git.php.net/?p=php-src.git;a=commit;h=a4252ab2be8a0231477396fd475397b23a089d0e