using variable instead of hardcoded name

Author: arcuri82

jdk_17_maven/em/embedded/rest/familie-ba-sak/src/main/java/em/embedded/familie/ba/sak/EmbeddedEvoMasterController.java

@@ -164,7 +164,7 @@ private AuthenticationDto getAuthenticationDto(String label, String oauth2Url){
         dto.loginEndpointAuth = x;
 
         x.externalEndpointURL = oauth2Url;
-        x.payloadRaw = "name="+label+"&grant_type=authorization_code&code=foo&client_id=foo";
+        x.payloadRaw = TOKEN_PARAM+"="+label+"&grant_type=authorization_code&code=foo&client_id=foo";
         x.verb = HttpVerb.POST;
         x.contentType = "application/x-www-form-urlencoded";
         x.expectCookies = false;