Updated pidgin packages fix security vulnerability

A server controlled by an attacker can send an invalid XML that can trigger an out-of-bound memory access. This might lead to a crash or, in some extreme cases, to remote code execution in the client-side (CVE-2017-2640). The pidgin package has been updated to version 2.12.0, which fixes this issue and other bugs, including certificate validation for the Google Talk protocol. It also removes protocol plugins for services that are no longer available or supported. See the upstream ChangeLog for details.