contrib/rpm: set runstatedir to "/run" instead of "/var/run"

Do so on all RHEL/Fedora releases. They all use systemd, and it's the right
choice for all of them.
12 jobs for th/build-runstatedir in 41 minutes and 23 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Test
passed #300857
allowed to fail
checkpatch

00:01:44

passed #300864
t_debian:9

00:14:52

passed #300866
t_debian:sid

00:14:44

manual #300865
allowed to fail manual
t_debian:testing
passed #300858
t_fedora:28

00:30:34

passed #300859
t_fedora:29

00:41:21

passed #300860
t_fedora:30

00:25:51

manual #300861
allowed to fail manual
t_fedora:rawhide
passed #300862
t_ubuntu:16.04

00:16:00

passed #300863
t_ubuntu:18.04

00:14:57

 
  External
passed NetworkManager test verification

passed NetworkManager test verification

06:20:21