bug#66167: 29.1; wrap-prefix text property with :align-to space keyword broken

[Paul W. Rankin]

Description:

The wrap-prefix text property with :align-to space keyword has been 
broken. (Regression).

To reproduce:

1. emacs -Q
2. in *scratch*, ensure visual-line-mode is enabled
3. insert enough text to wrap lines
4. M-: (put-text-property (point-min) (point-max) 'wrap-prefix '(space 
:align-to 10))

Expected results:

Wrapped text should align to column 10.

Actual result:

Wrapped text does not align. (No effect.)