String with `ns` in it confuses clojure-mode about the current ns

[borkdude]

Expected behavior

(ns myns)
(str "
(ns clojure.core)
")

(defn foo [_])

foo is now a defined function in namespace myns.

Actual behavior

foo is defined in the namespace clojure.core.

Steps to reproduce the problem

Eval the above example in a clojure-mode buffer.

Environment & Version information

clojure-mode version information

clojure-mode       20190313.1836

Emacs version

26.1 (9.0)

Operating system

MacOS