Add some hint to inspect the log-level

Setting the log-level of a Quarkus app to WARN to even less verbose can
break the detection of a successfully started application. This change
just adds a note to inspect those settings to the error message(s).

test-framework/common/src/main/java/io/quarkus/test/common/LauncherUtil.java

@@ -219,7 +219,8 @@ public CaptureListeningDataReader(Path processOutput, Duration waitTime, CountDo
         @Override
         public void run() {
             if (!ensureProcessOutputFileExists()) {
-                unableToDetermineData("Log file '" + processOutput.toAbsolutePath() + "' was not created.");
+                unableToDetermineData("Log file '" + processOutput.toAbsolutePath() + "' was not created. "
+                        + "Check if the options quarkus.log.level and quarkus.log.file.level are at least INFO (or more verbose).");
                 return;
             }
 
@@ -259,7 +260,8 @@ public void run() {
                                 dataDetermined(null, null); // no http, all is null
                             } else {
                                 unableToDetermineData("Waited " + waitTime.getSeconds() + " seconds for " + processOutput
-                                        + " to contain info about the listening port and protocol but no such info was found");
+                                        + " to contain info about the listening port and protocol but no such info was found. "
+                                        + "Check if the options quarkus.log.level and quarkus.log.file.level are at least INFO (or more verbose).");
                             }
                             return;
                         }