Select the current tab after displaying them

Call handleTabSelected right after displaying all tabs in the
LaunchConfigurationTabGroupViewer::displayInstanceTabs so that the
"activated" method of the tab is called.

Contributes to eclipse-pde/eclipse.pde#674

debug/org.eclipse.debug.ui/ui/org/eclipse/debug/internal/ui/launchConfigurations/LaunchConfigurationTabGroupViewer.java

@@ -878,6 +878,9 @@ protected void displayInstanceTabs(boolean redrawTabs) {
 		if (!fViewform.isVisible()) {
 			fViewform.setVisible(true);
 		}
+
+		// select the tab so that its "activated" method is called
+		handleTabSelected();
 	}
 
 	/**
@@ -1455,7 +1458,7 @@ protected void handleTabSelected() {
 			return;
 		}
 		ILaunchConfigurationTab[] tabs = getTabs();
-		if (fCurrentTabIndex == fTabFolder.getSelectionIndex() || tabs == null || tabs.length == 0 || fCurrentTabIndex > (tabs.length - 1)) {
+		if (tabs == null || tabs.length == 0 || fCurrentTabIndex > (tabs.length - 1)) {
 			return;
 		}
 		if (fCurrentTabIndex != -1) {