Check for null environment even if the artifact is present (#771)

Author: etanshaul

google-cloud-tools-plugin/src/com/google/cloud/tools/intellij/appengine/cloud/AppEngineArtifactDeploymentSourceType.java

@@ -67,10 +67,10 @@ public boolean apply(Artifact artifact) {
           }
       );
 
-      if (artifact.isPresent()) {
-        String environment = settings.getAttributeValue(
-            AppEngineDeploymentConfiguration.ENVIRONMENT_ATTRIBUTE);
+      String environment = settings.getAttributeValue(
+          AppEngineDeploymentConfiguration.ENVIRONMENT_ATTRIBUTE);
 
+      if (artifact.isPresent() && environment != null) {
         return new AppEngineArtifactDeploymentSource(
             AppEngineEnvironment.valueOf(environment),
             ArtifactPointerManager.getInstance(project).createPointer(artifact.get()));