Formatting regression

My `style.yapf`:
```
[style]
based_on_style = pep8
DEDENT_CLOSING_BRACKETS = true
```

I had a code like this:
```
def a():
class B:
def c(self):
self.fields['lorem'].label = (
'lorem ipsum dolor sit amet blah blah x'
)
```
and yapf seemed to like it, however after recent upgrade from 0.16.1 to 0.16.2 it started reformatting it to:
```
def a():
class B:
def c(self):
self.fields['lorem'
].label = ('lorem ipsum dolor sit amet blah blah x')
```

It seems like a terrible place for a newline. Any idea why it happens?