Fixes keyed each blocks for outro

Fixes #1706

src/compile/nodes/EachBlock.ts

@@ -331,7 +331,7 @@ export default class EachBlock extends Node {
 			${this.block.hasAnimation && `for (let #i = 0; #i < ${blocks}.length; #i += 1) ${blocks}[#i].a();`}
 		`);
 
-		if (this.compiler.options.nestedTransitions) {
+		if (this.block.hasOutros && this.compiler.options.nestedTransitions) {
 			const countdown = block.getUniqueName('countdown');
 			block.builders.outro.addBlock(deindent`
 				const ${countdown} = @callAfter(#outrocallback, ${blocks}.length);

test/runtime/samples/transition-js-nested-each-keyed-2/Widget.html

@@ -0,0 +1,3 @@
+{#each things as thing (thing)}
+  <div></div>
+{/each}

test/runtime/samples/transition-js-nested-each-keyed-2/_config.js

@@ -0,0 +1,13 @@
+export default {
+	nestedTransitions: true,
+
+	data: {
+		x: true,
+		things: ['a', 'b']
+	},
+
+	test(assert, component, target, window, raf) {
+		component.set({ x: false });
+		assert.htmlEqual(target.innerHTML, '');
+	},
+};

test/runtime/samples/transition-js-nested-each-keyed-2/main.html

@@ -0,0 +1,9 @@
+{#if x}
+	<Widget :things/>
+{/if}
+
+<script>
+	export default {
+		components: { Widget: './Widget.html' }
+	};
+</script>