Fix exceptions counter

lib/logstash-output-jdbc_ring-buffer.rb

@@ -14,6 +14,4 @@ class RingBuffer < Array
       self.push(el)
     end
   end
-
-  alias :push :<<
 end

lib/logstash/outputs/jdbc.rb

@@ -124,7 +124,8 @@ class LogStash::Outputs::Jdbc < LogStash::Outputs::Base
 
     if @exceptions_tracker.reject { |i| i.nil? }.count >= @max_flush_exceptions
       @logger.error("JDBC - max_flush_exceptions has been reached")
-      raise e
+      log_jdbc_exception(e)
+      raise LogStash::ShutdownSignal.new
     end
   end