[css-align] Remove the stretch=>start line in justify-self on blocks, as it looks like there's no reason to do so.

Author: tabatkins

css-align/Overview.bs

@@ -631,8 +631,6 @@ Inline/Main-Axis Alignment: the 'justify-self' property</h3>
 			are ignored in favor of alignment as specified here
 			and the used value of the offset properties are not adjusted to correct for the over-constraint.
 
-			The ''<item-position>/stretch'' value is equivalent to ''start'' on block-level boxes.
-
 			This property does not apply to floats.
 
 

css-align/Overview.html

@@ -737,8 +737,6 @@ <h3 class="heading settled" data-level=5.1 id=justify-self-property><span class=
 			are ignored in favor of alignment as specified here
 			and the used value of the offset properties are not adjusted to correct for the over-constraint.</p>
 
-<p>The <a class=css data-link-for="" data-link-type=maybe href=#valdef-item-position-stretch>stretch</a> value is equivalent to <a class=css data-link-type=maybe href=#valdef-item-position-content-position-start>start</a> on block-level boxes.</p>
-
 <p>This property does not apply to floats.</p>