feat(php) update the php min version

Signed-off-by: Benoit Mortier <benoit.mortier@fusiondirectory.org>

include/variables_common.inc

@@ -73,7 +73,7 @@ define("CONFIGRDN", "cn=config,ou=fusiondirectory,"); /*! Define FusionDirectory
 /*!
  * \brief Minimum PHP version
  */
-define('PHP_MIN_VERSION', '5.6.0');
+define('PHP_MIN_VERSION', '7.3.0');
 
 /*!
  * \brief Toggle crashing on PHP error, used for test suites