Merge pull request #2932 from evazion/fix-reltags-sqs

sqs_service.rb: fix exception when related tags sqs not configured.

app/logical/sqs_service.rb

@@ -5,8 +5,12 @@ class SqsService
     @url = url
   end
 
+  def enabled?
+    Danbooru.config.aws_sqs_enabled? && credentials.set? && url.present?
+  end
+
   def send_message(string, options = {})
-    return unless Danbooru.config.aws_sqs_enabled?
+    return unless enabled?
 
     sqs.send_message(
       options.merge(
@@ -18,16 +22,17 @@ class SqsService
 
 private
 
-  def sqs
+  def credentials
-    @sqs ||= begin
+    @credentials ||= Aws::Credentials.new(
-      credentials = Aws::Credentials.new(
       Danbooru.config.aws_access_key_id,
       Danbooru.config.aws_secret_access_key
     )
-      Aws::SQS::Client.new(
+  end
+
+  def sqs
+    @sqs ||= Aws::SQS::Client.new(
       credentials: credentials,
       region: Danbooru.config.aws_sqs_region
     )
   end
 end
-end