multimedia/webcamd: Variable "MK_REPRODUCIBLE_PATHS" is undefined

I'm trying to install x11-drivers/xf86-input-evdev, and this is one of its dependencies. It's been throwing that error for a while, and I can't continue the build unless I bypass that by installing the webcamd package instead.

Here's a fuller message:
```
[...]
make -C/usr/ports/multimedia/webcamd/work/webcamd-5.17.1.2/tools/linux_make
make[3]: /usr/share/mk/bsd.debug.mk:19: Variable "MK_REPRODUCIBLE_PATHS" is undefined
        in /usr/share/mk/bsd.prog.mk:362
        in /usr/share/multimedia/webcamd/work/webcamd-5.17.1.2/tools/linux_make/Makefile:12
        in make[3] in directory "/usr/ports/multimedia/webcamd/work/webcamd-5.17.1.2/tools/linux_make"
make[3]: Fatal errors encountered -- cannot continue
make[3]: stopped making "all" in /usr/ports/multimedia/webcamd/work/webcamd-5.17.1.2/tools/linux_make
*** Error code 1
```

Seems like it's a problem with the port build information, and not with webcamd itself···