update ratis version 3.2.1

Author: xichen01

pom.xml

@@ -204,7 +204,7 @@
     <protobuf-maven-plugin.version>0.6.1</protobuf-maven-plugin.version>
     <ranger.version>2.3.0</ranger.version>
     <ratis.thirdparty.version>1.0.6</ratis.thirdparty.version>
-    <ratis.version>3.1.2</ratis.version>
+    <ratis.version>3.2.1</ratis.version>
     <re2j.version>1.7</re2j.version>
     <reflections.version>0.10.2</reflections.version>
     <reload4j.version>1.2.26</reload4j.version>