[ha] Update pymysql to version 0.8

[ha] Update pymysql to version 0.8

* get latest pymysql from UCA repo
* set DB connection recycle time to avoid issue with broken database
  connection during query (MySQL server has gone away)
* set haproxy source balacing mode for neutron API to avoid race
  condition with duplicate security groups
* get libvirt/qemu from UCA repo on compute nodes since main process
  of libvirt exits (is killed by 11/SEGV [segfault]) during volume
  attaching operation

Change-Id: Iead5ecc561683876c476357f4a4de8780775aa7b
Signed-off-by: Michael Polenchuk <mpolenchuk@mirantis.com>