set class version when visit class

Author: lostsnow

dongtai-core/src/main/java/io/dongtai/iast/core/bytecode/enhance/plugin/core/DispatchClassPlugin.java

@@ -52,6 +52,13 @@ public class ClassVisit extends AbstractClassVisitor {
             };
         }
 
+        @Override
+        public void visit(int version, int access, String name, String signature, String superName,
+                          String[] interfaces) {
+            this.classVersion = version;
+            super.visit(version, access, name, signature, superName, interfaces);
+        }
+
         @Override
         public MethodVisitor visitMethod(final int access, final String name, final String descriptor,
                                          final String signature, final String[] exceptions) {