php: bump version to 7.1.0 (security)

Fixed CVEs:
 - CVE-2016-9933 (imagefilltoborder stackoverflow on truecolor images)
   http://bugs.php.net/72696
 - CVE-2016-9934 (NULL Pointer Dereference in WDDX Packet
   Deserialization with PDORow)
   http://bugs.php.net/73331

Full ChangeLog:
  http://php.net/ChangeLog-7.php#7.1.0

Signed-off-by: Vicente Olivert Riera <Vincent.Riera@imgtec.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/php/php.hash

@@ -1,2 +1,2 @@
 # From http://php.net/downloads.php
-sha256 0f1dff6392a1cc2ed126b9695f580a2ed77eb09d2c23b41cabfb41e6f27a8c89  php-7.0.14.tar.xz
+sha256 a810b3f29c21407c24caa88f50649320d20ba6892ae1923132598b8a0ca145b6  php-7.1.0.tar.xz

package/php/php.mk

@@ -4,7 +4,7 @@
 #
 ################################################################################
 
-PHP_VERSION = 7.0.14
+PHP_VERSION = 7.1.0
 PHP_SITE = http://www.php.net/distributions
 PHP_SOURCE = php-$(PHP_VERSION).tar.xz
 PHP_INSTALL_STAGING = YES