Fix issue with assigning a task

Author: ThomasKranitsas

src/services/ResourceService.js

@@ -223,7 +223,7 @@ async function init (currentUser, challengeId, resource, isCreated) {
   // Prevent from creating more than 1 submitter resources on tasks
   if (_.get(challenge, 'task.isTask', false) && isCreated && resource.roleId === config.SUBMITTER_RESOURCE_ROLE_ID) {
     const existing = await getResources(currentUser, challengeId, config.SUBMITTER_RESOURCE_ROLE_ID, 1, 1)
-    if (existing.total > 0) {
+    if (_.find(existing.data, r => r.roleId === config.SUBMITTER_RESOURCE_ROLE_ID)) {
       throw new errors.ConflictError(`The Task is already assigned`)
     }
   }