I think you should let this one go.

If you have to use pronouns in situations where you don't know the author's gender, there's always a chance you get it wrong. For example take most questions here on Academia.SE. If you have to refer to the question-asker in a situation where the gender is unknown, do you use 'he' or 'she'? It's either choose one and risk the possibility of getting it wrong, or write 'he or she' everywhere and end up with a very cumbersome answer (not to mention there's still a chance you get it wrong, since it's possible the question-asker identifies as transgender and prefers 'they').

That said, you could write something like this:

>The authors have addressed all the issues, and I recommend this paper for publication.
>
>PS: I'm female.

Writing something short like this is unlikely to make the editor groan, and he or she (or they) will probably pass your comment on to the authors. Editors don't usually censor reviewers - that only happens if there's something really inappropriate in the review, and this certainly isn't something inappropriate.