[css2] Correct misleading note

This closes w3c#1797

Author: frivoal

css2/visudet.html

@@ -1540,8 +1540,8 @@ <h3>10.8.1 <a name="leading">Leading and half-leading</a></h3>
 the largest font size.
 </p>
 <p class=note><em><strong>Note.</strong> When there is only one value of <a href="visudet.html#propdef-line-height" class="noxref"><span
-class="propinst-line-height">'line-height'</span></a> for all inline
-boxes in a block container box and they are all in the same font (and
+class="propinst-line-height">'line-height'</span></a> (other than 'normal') for all inline
+boxes in a block container box and they all use the same first available font (and
 there are no replaced elements, inline-block
 elements, etc.), the above will ensure that
 baselines of successive lines are exactly <a href="visudet.html#propdef-line-height" class="noxref"><span

css2/visudet.src

@@ -1433,8 +1433,8 @@ class="propinst-line-height">'line-height'</span> value according to
 the largest font size.
 </p>
 <p class=note><em><strong>Note.</strong> When there is only one value of <span
-class="propinst-line-height">'line-height'</span> for all inline
-boxes in a block container box and they are all in the same font (and
+class="propinst-line-height">'line-height'</span> (other than 'normal') for all inline
+boxes in a block container box and they all use the same first available font (and
 there are no replaced elements, inline-block
 elements, etc.), the above will ensure that
 baselines of successive lines are exactly <span