[oe] systemd service not enabled when adding simple recipe to image

[Sandro Stiller]

If anyone is interested:

The reason why systemd service works if installed using opkg and fails 
if I create an image:

The systemctl executable of OE is a shell script which handles the 
.service file in a different way.
I had a blank space behind the "WantedBy" line. The "real" systemctl has 
no problem with it, but the shell script silently ignores the entry 
without any error message and the service is not enabled in the image.