Backspace unindents by Tabsize even when not at the beginning of a line

Consider the following code (Cursor position marked by `|`):

int main()
{
  return 0;                              | // Returns to OS
}

Pressing backspace now does not delete a single space as in former versions, but up to tabsize spaces. This also happens when Creator is started with `-tcs`.

Expected: Backspace deletes exactly one space or tab character if there are non-whitespace characters before. It may delete tabsize spaces at once at the beginning of a line (unindent), but not in the middle or the end of a line.

Reason: I use spaces to align comments or tables and re-adjusting them is really hard now as I have to add spaces again after they has been removed by backspace.