NPE when searching for launch configs

Fixes #1574

Author: Bananeweizen

org.eclipse.m2e.launching/META-INF/MANIFEST.MF

@@ -2,7 +2,7 @@ Manifest-Version: 1.0
 Bundle-ManifestVersion: 2
 Bundle-Name: %Bundle-Name
 Bundle-SymbolicName: org.eclipse.m2e.launching;singleton:=true
-Bundle-Version: 2.0.600.qualifier
+Bundle-Version: 2.0.601.qualifier
 Bundle-Localization: plugin
 Require-Bundle: org.eclipse.core.runtime,
  org.eclipse.core.variables,

org.eclipse.m2e.launching/src/org/eclipse/m2e/actions/ExecutePomAction.java

@@ -399,6 +399,9 @@ private boolean showLaunches() {
   }
 
   private ILaunchConfiguration[] findLaunches(IContainer parent) {
+    if(parent == null) {
+      return new ILaunchConfiguration[0];
+    }
     try {
       List<ILaunchConfiguration> matchingConfigurations = ExecutePomAction
           .getMatchingConfigurations(parent.getLocation());