Updated ruby packages fix CVE-2014-8080

Updated ruby packages fix security vulnerability: Due to unrestricted entity expansion, when reading text nodes from an XML document, the REXML parser in Ruby can be coerced into allocating extremely large string objects which can consume all of the memory on a machine, causing a denial of service (CVE-2014-8080). The Mageia 3 ruby package has been updated to 1.9.3-p550 and the Mageia 4 ruby package has been updated to 2.0.0-p594 to fix this issue and several other bugs.