Connect github username with existing OCA

[Matthias Bläsing]

Hi,

I submitted a PR for OpenJFX (https://github.com/openjdk/jfx/pull/360)
and the skara tooling asks me to submit an OCA. I have had an OCA on
file for a long time since I began contributing to the netbeans
project. I also contributed to OpenJFX, so in general I assume this is
enough. I checked the OCA list signees and I'm listed.

So it is unclear whether I can just run "/signed" (as I already have an
OCA on file) or something else has to be done to connect my github
account with that OCA. The seconde paragraph indicates, that Authors,
Committers and Reviewers should open issues to get their username
connected, I'm neither, so I'd appreciate advise.

Thank you

Matthias