Fixed export by tags with a tag which contains space

src/Wallabag/CoreBundle/Controller/TagController.php

@@ -143,7 +143,7 @@ class TagController extends Controller
             'form' => null,
             'entries' => $entries,
             'currentPage' => $page,
-            'tag' => $tag->getLabel(),
+            'tag' => $tag->getSlug(),
         ]);
     }
 }

src/Wallabag/CoreBundle/DataFixtures/ORM/LoadTagData.php

@@ -15,7 +15,7 @@ class LoadTagData extends AbstractFixture implements OrderedFixtureInterface
     public function load(ObjectManager $manager)
     {
         $tag1 = new Tag();
-        $tag1->setLabel('foo');
+        $tag1->setLabel('foo bar');
 
         $manager->persist($tag1);