revert spotless plugin to 2.1.0

Author: yue9944882

pom.xml

@@ -334,7 +334,7 @@
       <plugin>
         <groupId>com.diffplug.spotless</groupId>
         <artifactId>spotless-maven-plugin</artifactId>
-        <version>2.4.1</version>
+        <version>2.1.0</version>
         <configuration>
           <formats>
             <format>