php: security bump to version 5.5.16

Fixes:
CVE-2014-3538 - Extensive backtracking in rule regular expression
CVE-2014-3587 - Segfault in cdf.c
CVE-2014-2497 - php-gd 'c_color' NULL pointer dereference
CVE-2014-5120 - Null byte injection possible with imagexxx functions
CVE-2014-3597 - segfault in dns_get_record

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>