Fixed duplicated tags creation

Change-Id: I59100984ed54aad9f2c1b1fb3c0331065ecb4e29

app/Repositories/Main/DoctrineTagRepository.php

@@ -59,7 +59,8 @@ final class DoctrineTagRepository
                 ->from(\models\main\Tag::class, "t")
                 ->where('UPPER(TRIM(t.tag)) = UPPER(TRIM(:tag))')
                 ->setParameter('tag', $tag)
-                ->getQuery()->getFirstResult();
+                ->setMaxResults(1)
+                ->getQuery()->getOneOrNullResult();
         }
         catch(NoResultException $e){
             return null;

app/Services/Apis/ExternalScheduleFeeds/Implementations/VanderpoelScheduleFeed.php

@@ -73,12 +73,23 @@ final class VanderpoelScheduleFeed extends AbstractExternalScheduleFeed
                 'start_date'  => $event['start_timestamp'],
                 'end_date'    => $event['end_timestamp'],
                 'speakers'    => $speakers,
-                'tags'        => utf8_encode($event["keywords"])
+                'tags'        => self::encode_array($event["keywords"])
             ];
         }
         return $events;
     }
 
+    private static function encode_array($array){
+        if(is_array($array)){
+            $res = [];
+            foreach ($array as $element){
+                $res[] = utf8_encode($element);
+            }
+            return $res;
+        }
+        return $array;
+    }
+
     public function getSpeakers(): array
     {
         return $this->speakers;