[web-animations-1] Fix indentation after automated spec change

Author: birtles

web-animations-1/Overview.bs

@@ -4433,7 +4433,7 @@ abstract {{AnimationEffect}} interface.
 interface AnimationEffect {
     EffectTiming         getTiming();
     ComputedEffectTiming getComputedTiming();
-    undefined                 updateTiming(optional OptionalEffectTiming timing = {});
+    undefined            updateTiming(optional OptionalEffectTiming timing = {});
 };
 </pre>
 
@@ -4816,7 +4816,7 @@ interface KeyframeEffect : AnimationEffect {
     attribute CSSOMString?       pseudoElement;
     attribute CompositeOperation composite;
     sequence&lt;object&gt; getKeyframes();
-    undefined             setKeyframes(object? keyframes);
+    undefined        setKeyframes(object? keyframes);
 };
 </pre>