Accept value */*;text/html; causes Json2XmlValidator to return XML instead of JSON
**❗ please do not add sensitive information in issues, you can provide extra information via email using issue number as reference ❗**

**Describe the issue**
When having an ApiListener with `produces="JSON"` and using the Json2XmlInputValidator to handle data conversion, we would like to respond with JSON.

When a consumer specifies the following Accept header: `*/*;text/html` the consumes check succeeds due to `*/*` but the following code block fails here and will return `text/html` as outputFormat.

Causing errors when translating response that text/html is not a valid value, should be JSON or XML.

Introduced in #5127:
![image](https://github.com/ibissource/iaf/assets/37303445/24346004-cf33-401c-a130-f825ddac7e7d)

![image](https://github.com/ibissource/iaf/assets/37303445/33f81da3-326f-46a6-b870-db0e3f2b62db)


diff --git a/core/src/main/java/nl/nn/adapterframework/pipes/Json2XmlValidator.java b/core/src/main/java/nl/nn/adapterframework/pipes/Json2XmlValidator.java
index 70d668310..d800e076f 100644
--- a/core/src/main/java/nl/nn/adapterframework/pipes/Json2XmlValidator.java
+++ b/core/src/main/java/nl/nn/adapterframework/pipes/Json2XmlValidator.java
@@ -146,10 +146,10 @@ public class Json2XmlValidator extends XmlValidator implements HasPhysicalDestin
 	}
 
 	/**
-	 * Default format has precedence over the accept header, accept header may be invalid or * slash *, in which case it should be ignored. First accept value wins.
+	 * Default format has precedence over the accept header, accept header may be invalid or * slash *, in case of * slash * it means any content-type is accepted for the consumer, defaults to detected output format.
 	 */
 	private String parseAcceptHeader(DocumentFormat detectedFormat, String acceptHeaderValue) {
-		if(StringUtils.isEmpty(acceptHeaderValue) || "*/*".equals(acceptHeaderValue)) {
+		if(StringUtils.isEmpty(acceptHeaderValue) || acceptHeaderValue.contains("*/*")) {
 			return detectedFormat.name();
 		}
 
['core/src/main/java/nl/nn/adapterframework/pipes/Json2XmlValidator.java']