Clarifying exception message

Author: dougqh

dd-java-agent/testing/src/main/groovy/datadog/trace/agent/test/utils/PortUtils.java

@@ -124,7 +124,7 @@ public static void waitForPortToOpen(
                   + port
                   + " was opened");
         } else {
-          throw new RuntimeException("Process died before port=" + port + " was opened");
+          throw new RuntimeException("Process finished before port=" + port + " was opened");
         }
       }