ICore: Don't split context in contextChanged signal

This way the order of the context doesn't get lost between context from
the focus widget and additional contexts

Change-Id: I371c411a5d9c9f31ae1f8631a6ede4eda100b0c5
Reviewed-by: David Schulz <david.schulz@theqtcompany.com>

src/plugins/coreplugin/mainwindow.cpp

@@ -1024,7 +1024,7 @@ void MainWindow::updateContext()
     }
 
     ActionManager::setContext(uniquecontexts);
-    emit m_coreImpl->contextChanged(m_activeContext, m_additionalContexts);
+    emit m_coreImpl->contextChanged(uniquecontexts);
 }
 
 void MainWindow::aboutToShowRecentFiles()