This was added in 6cdc4ba6cd in 2016, likely
because at the time we were still building for CentOS 6 and Ubuntu 14.04.
All currently supported distros appear to be on _at least_ 219 now, so it looks
safe to remove this;
```bash
docker run -it --rm centos:7
yum install -y systemd-devel
pkg-config 'libsystemd >= 209' && echo "OK" || echo "KO"
OK
pkg-config --print-provides 'libsystemd'
libsystemd = 219
pkg-config --print-provides 'libsystemd-journal'
libsystemd-journal = 219
```
And on a `debian:buster` (old stable)
```bash
docker run -it --rm debian:buster
apt-get update && apt-get install -y libsystemd-dev pkg-config
pkg-config 'libsystemd >= 209' && echo "OK" || echo "KO"
OK
pkg-config --print-provides 'libsystemd'
libsystemd = 241
pkg-config --print-provides 'libsystemd-journal'
Package libsystemd-journal was not found in the pkg-config search path.
Perhaps you should add the directory containing `libsystemd-journal.pc'
to the PKG_CONFIG_PATH environment variable
No package 'libsystemd-journal' found
```
OpenSUSE leap (I think that's built for s390x)
```bash
docker run -it --rm docker.io/opensuse/leap:15
zypper install -y systemd-devel
pkg-config 'libsystemd >= 209' && echo "OK" || echo "KO"
OK
pkg-config --print-provides 'libsystemd'
libsystemd = 246
pkg-config --print-provides 'libsystemd-journal'
Package libsystemd-journal was not found in the pkg-config search path.
Perhaps you should add the directory containing `libsystemd-journal.pc'
to the PKG_CONFIG_PATH environment variable
No package 'libsystemd-journal' found
```
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
0e9a66d35a