make TimestampRange Getter accessible (#97)

Author: wankai123

src/main/java/org/apache/skywalking/banyandb/v1/client/TimestampRange.java

@@ -19,7 +19,6 @@
 package org.apache.skywalking.banyandb.v1.client;
 
 import com.google.protobuf.Timestamp;
-import lombok.AccessLevel;
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
 import lombok.ToString;
@@ -28,7 +27,7 @@
 import org.apache.skywalking.banyandb.v1.client.util.TimeUtils;
 
 @RequiredArgsConstructor
-@Getter(AccessLevel.PROTECTED)
+@Getter
 @ToString
 public class TimestampRange {
     static final BanyandbModel.TimeRange MAX_RANGE = BanyandbModel.TimeRange.newBuilder()