Bug 571109 - NPE when running a docker image

- add null check to ImageRun.getDockerContainerConfig() for
  selected ports

Change-Id: I8557db4e5e37433d8221032095c54e4c5edd1993
Reviewed-on: https://git.eclipse.org/r/c/linuxtools/org.eclipse.linuxtools/+/176215
Tested-by: Linux Tools Bot <linuxtools-bot@eclipse.org>
Reviewed-by: Jeff Johnston <jjohnstn@redhat.com>
diff --git a/containers/org.eclipse.linuxtools.docker.ui/src/org/eclipse/linuxtools/internal/docker/ui/wizards/ImageRun.java b/containers/org.eclipse.linuxtools.docker.ui/src/org/eclipse/linuxtools/internal/docker/ui/wizards/ImageRun.java
index 400954d..65713c8 100644
--- a/containers/org.eclipse.linuxtools.docker.ui/src/org/eclipse/linuxtools/internal/docker/ui/wizards/ImageRun.java
+++ b/containers/org.eclipse.linuxtools.docker.ui/src/org/eclipse/linuxtools/internal/docker/ui/wizards/ImageRun.java
@@ -267,7 +267,8 @@
 			final Set<String> exposedPorts = new HashSet<>();
 			for (ExposedPortModel exposedPort : selectionModel.getExposedPorts()) {
 				// only selected Ports in the CheckboxTableViewer are exposed.
-				if (!selectionModel.getSelectedPorts().contains(exposedPort)) {
+				if (selectionModel.getSelectedPorts() == null
+						|| !selectionModel.getSelectedPorts().contains(exposedPort)) {
 					continue;
 				}
 				exposedPorts.add(exposedPort.getContainerPort()