ODE allows activating a retired process when there is already an active version

Steps to reproduce:
1) Deploy a process to the server (V1)
2) Deploy the process again (V2)
3) V1: Retired and V2: Active
4) Now activate (Process package) V1 which is in Retired state.
5) An exception is thrown ContextException("Can't activate two processes of the same name:....)
6) Now check the status of V1 and V2, you can see that both the versions V1 and V2 are Active.

Retired process should not be activated when there is already an active version.

Forum Thread
http://ode.markmail.org/message/a6mihchounrue4yz