Bad formatting in long function arguments with conditional expression

Hi!

I have a code that calls with complex arguments, and some of them have conditional expression.
For example, the code below is the minimal exploit that show this issue:
```python
def foo():
return call.me.by.dot(
key1=val1,
key2=val2,
key3=self._val_helper(
other.helper(
val1,
keykey1=val2,
keykey2=val3,
keykey3=val4,
keykey4=val5,
keykeykey=val3) if self._long_long_foo() else ()))
```

For the exploit, I ran yapf with `--style='{based_on_style=pep8, column_limit=50}'` option.

Since the `self._long_long_foo()` exceeds the column limit, I thought that whole `self._long_long_foo()` should be wrapped after formatting, but it wasn't:

```python
def foo():
return call.me.by.dot(
key1=val1,
key2=val2,
key3=self._val_helper(
other.helper(val1,
keykey1=val2,
keykey2=val3,
keykey3=val4,
keykey4=val5,
keykeykey=val3) if self.
_long_long_foo() else ()))
```

I think it is better to format not to wrap before the dot in `self.`, but to wrap before `if`, so that the reformatted code should look at least like:
```python
def foo():
return call.me.by.dot(
key1=val1,
key2=val2,
key3=self._val_helper(
other.helper(
val1,
keykey1=val2,
keykey2=val3,
keykey3=val4,
keykey4=val5,
keykeykey=val3) if
self._long_long_foo() else ()))
```
or, for the best,
```python
def foo():
return call.me.by.dot(
key1=val1,
key2=val2,
key3=self._val_helper(
other.helper(
val1,
keykey1=val2,
keykey2=val3,
keykey3=val4,
keykey4=val5,
keykeykey=val3)
if self._long_long_foo() else ()))
```

What do you think about this? It would be grateful if you consider this issue.
Thank you!