Bug 542742: [JUnit 5] Avoid calling Launcher#discover

Change-Id: I773fb793df6538835e7f7dee36c85aa49c2d8679
diff --git a/org.eclipse.jdt.junit5.runtime/src/org/eclipse/jdt/internal/junit5/runner/JUnit5TestReference.java b/org.eclipse.jdt.junit5.runtime/src/org/eclipse/jdt/internal/junit5/runner/JUnit5TestReference.java
index 26c2b9a..e5e40a8 100644
--- a/org.eclipse.jdt.junit5.runtime/src/org/eclipse/jdt/internal/junit5/runner/JUnit5TestReference.java
+++ b/org.eclipse.jdt.junit5.runtime/src/org/eclipse/jdt/internal/junit5/runner/JUnit5TestReference.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2016, 2017 IBM Corporation and others.
+ * Copyright (c) 2016, 2019 IBM Corporation and others.
  *
  * This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License 2.0
@@ -86,7 +86,7 @@
 
 	@Override
 	public void run(TestExecution execution) {
-		fLauncher.execute(fRequest, new JUnit5TestListener(execution.getListener(), fRemoteTestRunner));
+		fLauncher.execute(fTestPlan, new JUnit5TestListener(execution.getListener(), fRemoteTestRunner));
 	}
 
 	@Override