Update computed value lines to reference computed <image>. w3c#4042

Author: fantasai

fill-stroke/Overview.bs

@@ -309,7 +309,7 @@ Fill Paint {#fill-paint}
 		Inherited: yes
 		Percentages: N/A
 		Media: visual
-		Computed value: as specified, with URLs made absolute
+		Computed value: as specified, with any <<image>> computed
 		Animatable: as repeatable list of images
 	</pre>
 
@@ -1222,7 +1222,7 @@ Stroke Paint {#stroke-paint}
 		Inherited: yes
 		Percentages: N/A
 		Media: visual
-		Computed value: as specified, with URLs made absolute
+		Computed value: as specified, with any <<image>> computed
 		Animatable: as repeatable list of images
 	</pre>