BUG #12746: Backward compatibility is broken 9.2: pg_stat_activity.procpid renamed to pid

The following bug has been logged on the website:

Bug reference:      12746
Logged by:          Rad Cirskis
Email address:      nad2000@gmail.com
PostgreSQL version: 9.2.0
Operating system:   Linux
Description:

I run an app that should support both 9.0 and 9.4. I found that at 9.2 the
pg_stat_activity column porcpid was renamed to pid. It broke the app. To
solve it I had to introduce conditional querying for different versions.
I don't think it's right time to do any aesthetically motivated changes at
this stage.