Added check for hasHttpSignatureMethods. (#14339)

Author: s-jepsen

modules/openapi-generator/src/main/resources/Java/libraries/jersey3/ApiClient.mustache

@@ -1234,7 +1234,12 @@ public class ApiClient{{#jsr310}} extends JavaTimeFormatter{{/jsr310}} {
         queryParams,
         allHeaderParams,
         cookieParams,
+        {{#hasHttpSignatureMethods}}
         serializeToString(body, formParams, contentType, isBodyNullable),
+        {{/hasHttpSignatureMethods}}
+        {{^hasHttpSignatureMethods}}
+        null,
+        {{/hasHttpSignatureMethods}}
         method,
         target.getUri());