change java version to 11

pom.xml

@@ -24,7 +24,7 @@
         <revision>2.0</revision>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <maven.compiler.version>3.8.1</maven.compiler.version>
-        <java.version>13</java.version>
+        <java.version>11</java.version>
         <bouncy.castle.version>1.65</bouncy.castle.version>
         <lombok.version>1.18.12</lombok.version>
         <log4j.version>1.7.30</log4j.version>