Merge pull request #300 from wok/master

Fix warning about already defined EXPLAINED_SQLS

Author: metaskills

lib/active_record/connection_adapters/sqlserver/core_ext/explain_subscriber.rb

@@ -1 +1,4 @@
-ActiveRecord::ExplainSubscriber::EXPLAINED_SQLS = /(select|update|delete|insert)\b/i
+silence_warnings do
+  # Already defined in Rails
+  ActiveRecord::ExplainSubscriber::EXPLAINED_SQLS = /(select|update|delete|insert)\b/i
+end