Hi!

Cljr fails to rename symbol in code which is successfully compiled and run bylein test.

Expected behavior

1. cd /Users/YourName/Desktop.
2. git clone https://github.com/developer2019/example
3. Open /Users/YourName/Desktop/example/src/anagram.clj in Emacs.
4. M-x cider-mode
5. <menu-bar> <CIDER> <Start a REPL>
6. Position cursor at anagrams-for (line 4, symbol 10) and press M-x cljr-rename-symbol RET.
   It tells that project needs to be evaluated, type y RET.
7. Cljr should ask for a new symbol name and then rename this symbol in all project files.

Actual behavior

1. cd /Users/YourName/Desktop.
2. git clone https://github.com/developer2019/example
3. Open /Users/YourName/Desktop/example/src/anagram.clj in Emacs.
4. M-x cider-mode
5. <menu-bar> <CIDER> <Start a REPL>
6. Position cursor at anagrams-for (line 4, symbol 10) and press M-x cljr-rename-symbol RET.
   It tells that project needs to be evaluated, type y RET.
7. It fails with Wrong type argument: char-or-string-p, nil.

Steps to reproduce the problem

1. cd /Users/YourName/Desktop.
2. git clone https://github.com/developer2019/example
3. Open /Users/YourName/Desktop/example/src/anagram.clj in Emacs.
4. M-x cider-mode
5. <menu-bar> <CIDER> <Start a REPL>
6. Position cursor at anagrams-for (line 4, symbol 10) and press M-x cljr-rename-symbol RET.
   It tells that project needs to be evaluated, type y RET.
7. It fails with Wrong type argument: char-or-string-p, nil.

Environment & Version information

lein test compiles this code and runs successfully.

clj-refactor.el version information

clj-refactor 2.4.0-SNAPSHOT (package: 20171117.317), refactor-nrepl 2.4.0-SNAPSHOT from MELPA (i. e. latest clj-refactor).

CIDER version information

;; CIDER 0.15.1 (London), nREPL 0.2.12
;; Clojure 1.8.0, Java 1.8.0_111

Leiningen or Boot version

$ lein --version
Leiningen 2.8.1 on Java 1.8.0_111 Java HotSpot(TM) 64-Bit Server VM

lein test compiles this project and runs successfully.

Emacs version

GNU Emacs 25.3.1

Operating system

OS X 10.11 "El Capitan"