add PoolPausedError as retryable

Author: joelim41

lib/mongo/retryable/base_worker.rb

@@ -60,6 +60,7 @@ def retryable_exceptions
           Error::SocketError,
           Error::SocketTimeoutError,
           Error::PoolClearedError,
+          Error::PoolPausedError,
         ].freeze
       end