fix pom version error

Author: aaronshan

README.md

@@ -35,7 +35,7 @@ It will generate hive-third-functions-${version}-shaded.jar in target directory.
 
 You can also directly download file from [release page](https://github.com/aaronshan/hive-third-functions/releases).
 
-> current latest version is `2.2.1`
+> current latest version is `2.1.1`
 
 ## Functions
 

pom.xml

@@ -6,7 +6,7 @@
 
     <groupId>cc.shanruifeng</groupId>
     <artifactId>hive-third-functions</artifactId>
-    <version>2.2.1</version>
+    <version>2.1.1</version>
 
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>