Which OS do you use? How did you install?
I have an unmodified Windows install (with the official installer), and the entry does exist.
I haven't tested other OS.
Anyway if you build yourself, or if you rebuild (and maybe something was in your old config / I haven't seen it happen yet, but maybe...) then maybe the relevant package did get un-installed (or was never installed if you did build from source).
In any case, install the package "DockedFormEditor", then the entry should appear in the options, and you can enable it.