`cljr-clean-ns` removes used CLJS import

## Expected behavior

`cljr-clean-ns` does not remove used import.

## Actual behavior

In a CLJS file, given the following:

```clojure
(ns foo.bar
(:import [goog.i18n NumberFormat]
[goog.i18n.NumberFormat Format]))

(defn money [n]
(let [fmt (NumberFormat. Format.CURRENCY)]
(.format fmt n)))
```

`cljr-clean-ns` removes the `goog.i18n.NumberFormat Format` import.

## Steps to reproduce the problem

As above

## Environment & Version information

### clj-refactor.el version information

```
clj-refactor 2.4.0-SNAPSHOT (package: 20171117.317), refactor-nrepl 2.4.0-SNAPSHOT
```

### CIDER version information

```
;; CIDER 0.16.0snapshot (package: 20171001.112), nREPL 0.2.13
;; Clojure 1.9.0, Java 1.8.0_151
```

### Leiningen or Boot version

`Leiningen 2.8.1`

### Emacs version

`26.0.50`

### Operating system

`OS X 10.11.6 "El Capitan"`