Fixes error message

lib/gitlab/ci/yaml_processor/dag.rb

@@ -23,7 +23,7 @@ module Gitlab
 
           new(nodes).tsort
         rescue TSort::Cyclic
-          raise ValidationError, 'The pipeline has circular dependencies.'
+          raise ValidationError, 'The pipeline has circular dependencies'
         rescue MissingNodeError
         end
 

spec/lib/gitlab/ci/yaml_processor_spec.rb

@@ -2851,7 +2851,7 @@ module Gitlab
             YAML
           end
 
-          it_behaves_like 'returns errors', 'The pipeline has circular dependencies.'
+          it_behaves_like 'returns errors', 'The pipeline has circular dependencies'
         end
       end