clojure.repl/doc repeats doc string in output for special forms in Clojure 1.9.0

Here is output from Clojure 1.8.0:

Here is the corresponding output from Clojure 1.9.0:

This repetition only occurs when calling clojure.repl/doc or clojure.repl/print-doc for special form symbols, not for other symbols like macros and functions. It was introduced when modifying clojure.repl/print-doc when adding the ability to print specs in its output, and the fix is straightforward.

Prescreened by: Alex Miller