Fixed the bug that 'back-to-indentation' operation breaks "." repeating

[York Zhao]

>> Please find attached my patch file to fix the bug as described in the title.

> Sorry I should have explained this in a little more details.
>
> The problem was that if you make some changes, then press "M-m" (key binding for
> the `back-to-indentation') to get to the first non-whitespace character of the
> current line, you wouldn't be able to repeat anything afterwards. This was what
> this patch trying to address.
>
> To me, 'back-to-indentation' is handy because I feel it is easier than pressing
> "0" plus "w".

May I ask why this fix seemed to not have been wanted?