Correct custom json deserializer's base class.

spring-boot-admin-server/src/main/java/de/codecentric/boot/admin/server/domain/values/Registration.java

@@ -30,11 +30,11 @@ import org.springframework.util.StringUtils;
 import com.fasterxml.jackson.core.JsonGenerator;
 import com.fasterxml.jackson.core.JsonParser;
 import com.fasterxml.jackson.databind.DeserializationContext;
-import com.fasterxml.jackson.databind.JsonDeserializer;
 import com.fasterxml.jackson.databind.JsonNode;
 import com.fasterxml.jackson.databind.SerializerProvider;
 import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
 import com.fasterxml.jackson.databind.annotation.JsonSerialize;
+import com.fasterxml.jackson.databind.deser.std.StdDeserializer;
 import com.fasterxml.jackson.databind.ser.std.StdSerializer;
 
 /**
@@ -139,7 +139,11 @@ public class Registration implements Serializable {
         }
     }
 
-    public static class Deserializer extends JsonDeserializer<Registration> {
+    public static class Deserializer extends StdDeserializer<Registration> {
+        protected Deserializer() {
+            super(Registration.class);
+        }
+
         @Override
         public Registration deserialize(JsonParser p, DeserializationContext ctxt) throws IOException {
             JsonNode node = p.readValueAsTree();