add javadoc intention should be unavailable if javadoc already exists IDEA-174275

java/java-tests/testData/codeInsight/addJavadoc/beforeJavadocAlreadyExists.java

@@ -0,0 +1,7 @@
+// "Add Javadoc" "false"
+/**
+ * javadoc
+ */
+class F<caret>oo {
+
+}