Better handling of indented multiline if/elseif.

See #162.

Fixes the behaviour where:

```php
<?php

    if (
        true &&
        true
    ) {
        // ...
    } elseif (
        true &&
        true
    ) {
        // ...
    }
```

Is incorrectly fixed to:

```php
<?php

    if (
        true &&
        true
) {
        // ...
    } elseif (
        true &&
        true
) {
        // ...
    }
```