Wrong indentation for opening curly brace for =, += and -= operator overloads

The opening curly brace indentation for the =, += and -= operator overloads is incorrect, it is indented far too much:

inline QString &operator+=(QChar::SpecialCharacter c)
                          {
    return append(QChar(c));
}

This problem does not occur for other operator overloads like ==, != and >=.