Dilato: Core: The rename function doesn't work from the second time

[ZuoBaogang]

Testing build: 1.12.0-17613-971

1. Launch Brackets
2. Open a JS file
3. Try to Rename a function name use Refactor -> Reanme
4. Change the function name
5. Repeat the step 3 again

Result: The rename function doesn't work

Expect: The Refactor -> Reanme function works well or give an error message

[ZuoBaogang]

Verified this issue on build 1.12.0-17621-984, fixed

[nethip]

@navch Can you have a look at this?