AutoTest: Avoid replacing a correct executable

If we already had a correct executable we might end up using
the wrong one when trying to complete the configuration again.
So, if the former configuration already had an executable set
do not try to complete the configuration again.

Change-Id: I270be71d87b311c6a5eaad14e0d5a2de60353e5d
Reviewed-by: Oliver Wolff <oliver.wolff@qt.io>

src/plugins/autotest/testconfiguration.cpp

@@ -76,6 +76,10 @@ void TestConfiguration::completeTestInformation(ProjectExplorer::RunConfiguratio
                                                 TestRunMode runMode)
 {
     QTC_ASSERT(rc, return);
+    if (hasExecutable()) {
+        qCDebug(LOG) << "Executable has been set already - not completing configuration again.";
+        return;
+    }
     Project *project = SessionManager::startupProject();
     if (!project)
         return;