Do not warn on make complaining about "Nothing to be done"

src/plugins/projectexplorer/gnumakeparser.cpp

@@ -70,6 +70,8 @@ void GnuMakeParser::stdOutput(const QString &line)
     if (m_makeLine.indexIn(lne) > -1) {
         if (!m_alreadyFatal) {
             QString message = m_makeLine.cap(4);
+            if (message.startsWith("Nothing to be done for "))
+                return;
             Task task(Task::Warning,
                       message,
                       QString() /* filename */,
@@ -249,6 +251,14 @@ void ProjectExplorerPlugin::testGnuMakeParserParsing_data()
                         Constants::TASK_CATEGORY_BUILDSYSTEM))
             << QString()
             << QStringList();
+    QTest::newRow("Nothing to be done")
+            << QStringList()
+            << QString::fromLatin1("make[2]: Nothing to be done for `first.")
+            << OutputParserTester::STDOUT
+            << QString() << QString()
+            << QList<Task>()
+            << QString()
+            << QStringList();
 }
 
 void ProjectExplorerPlugin::testGnuMakeParserParsing()