feat(matrix ui): do not log validation errors

Author: bethesque

lib/pact_broker/ui/controllers/matrix.rb

@@ -32,7 +32,7 @@ class Matrix < Base
               end
             end
           rescue StandardError => e
-            log_error e
+            log_error(e) unless e.is_a?(PactBroker::Error)
             locals[:errors] = [e.message]
           end
           haml :'matrix/show', {locals: locals, layout: :'layouts/main'}