ParsableHeaderValue::parameter does not call ensureHeaderProcessed
`ParsableHeaderValue::parameter` does not call `ensureHeaderProcessed`. Because of this, the function will return `null` even though there is a parameter.

Same goes for `parameters`

Workaround is to call `value` first
diff --git a/vertx-web/src/main/java/io/vertx/ext/web/impl/ParsableHeaderValue.java b/vertx-web/src/main/java/io/vertx/ext/web/impl/ParsableHeaderValue.java
index 596d7071e..b46cdfd77 100644
--- a/vertx-web/src/main/java/io/vertx/ext/web/impl/ParsableHeaderValue.java
+++ b/vertx-web/src/main/java/io/vertx/ext/web/impl/ParsableHeaderValue.java
@@ -54,10 +54,12 @@ public class ParsableHeaderValue implements ParsedHeaderValue {
   }
 
   public String parameter(String key) {
+    ensureHeaderProcessed();
     return parameter.get(key);
   }
 
   public Map<String, String> parameters() {
+    ensureHeaderProcessed();
     return Collections.unmodifiableMap(parameter);
   }
 
['vertx-web/src/main/java/io/vertx/ext/web/impl/ParsableHeaderValue.java']