[css-inline-3] Fix link

Author: fantasai

css-inline-3/Overview.bs

@@ -958,7 +958,7 @@ Sizing Initial Letters</h3>
 	The line height used in this calculation
 	is the 'line-height' of the containing block
 	(or, in the case where a baseline grid is in use,
-	the baseline-to-baseline spacing required by the baseline grid [[CSS-LINE-GRID-3]]).
+	the baseline-to-baseline spacing required by the baseline grid [[CSS-LINE-GRID-1]]).
 	The contents of the lines spanned,
 	and therefore any variation in their heights and positions,
 	is not accounted for.