Merge pull request #173 from magento/168-fixed-null-pointer-exception

Fixed null pointer exception on ObserverDeclarationInspection

Author: Vitaliy

src/com/magento/idea/magento2plugin/inspections/xml/ObserverDeclarationInspection.java

@@ -71,6 +71,9 @@ public void visitFile(PsiFile file) {
                     }
 
                     List<XmlTag> targetObservers = fetchObserverTagsFromEventTag(eventXmlTag);
+                    if (targetObservers.isEmpty()) {
+                        continue;
+                    }
 
                     for (XmlTag observerXmlTag: targetObservers) {
                         XmlAttribute observerNameAttribute = observerXmlTag.getAttribute("name");