RSPEC-3403 FP The "prop" in "for (prop in object)" is not considered a string

[RoDo777 (Roland D.)]

@saberduck This is a special answer to aercolino, because (I believe) that he thinks sonarqube analyzes at runtime:

BUT [“prop” does hold a string].
And Lena can’t reproduce, because the question was confusing

Btw: Is someone looking at my bug report
(RSPEC-3403 is useless, and should be removed - the statement “it will always be true” is not correct, the rule therefore useless)