Remove unused import

Author: jeffwidman

kafka/producer/record_accumulator.py

@@ -10,7 +10,6 @@
 from kafka.producer.buffer import SimpleBufferPool
 from kafka.producer.future import FutureRecordMetadata, FutureProduceResult
 from kafka.record.memory_records import MemoryRecordsBuilder
-from kafka.record.legacy_records import LegacyRecordBatchBuilder
 from kafka.structs import TopicPartition