Removed a redundant import

Author: Vitaliy Boyko

src/com/magento/idea/magento2plugin/stubs/indexes/xml/PhpClassNameIndex.java

@@ -7,7 +7,6 @@
 
 import com.intellij.ide.highlighter.XmlFileType;
 import com.intellij.psi.PsiFile;
-import com.intellij.psi.impl.source.xml.XmlTagImpl;
 import com.intellij.psi.util.PsiTreeUtil;
 import com.intellij.psi.xml.XmlAttribute;
 import com.intellij.psi.xml.XmlFile;