Add simple workaround for empty file issue

We tried to do more complicated things but in the timeframe we had, ran
into some hard-to-trace issues on SLES of all things. This fix is
simple, kinda stupid, and should just work. Because there are two
codepaths that (previously) called keytool commands which could error
out on an empty target file, the new empty file hack is installed in its
own dedicated method.