C#: Remove the cs/xmldoc/missing-xmldoc from the code-quality-extended.

Author: michaelnebel

csharp/ql/integration-tests/posix/query-suite/csharp-code-quality-extended.qls.expected

@@ -47,7 +47,6 @@ ql/csharp/ql/src/Concurrency/UnsynchronizedStaticAccess.ql
 ql/csharp/ql/src/Dead Code/DeadStoreOfLocal.ql
 ql/csharp/ql/src/Documentation/XmldocExtraParam.ql
 ql/csharp/ql/src/Documentation/XmldocExtraTypeParam.ql
-ql/csharp/ql/src/Documentation/XmldocMissing.ql
 ql/csharp/ql/src/Documentation/XmldocMissingSummary.ql
 ql/csharp/ql/src/Language Abuse/CastThisToTypeParameter.ql
 ql/csharp/ql/src/Language Abuse/CatchOfGenericException.ql

csharp/ql/integration-tests/posix/query-suite/not_included_in_qls.expected

@@ -20,6 +20,7 @@ ql/csharp/ql/src/Dead Code/DeadRefTypes.ql
 ql/csharp/ql/src/Dead Code/NonAssignedFields.ql
 ql/csharp/ql/src/Dead Code/UnusedField.ql
 ql/csharp/ql/src/Dead Code/UnusedMethod.ql
+ql/csharp/ql/src/Documentation/XmldocMissing.ql
 ql/csharp/ql/src/Documentation/XmldocMissingException.ql
 ql/csharp/ql/src/Documentation/XmldocMissingParam.ql
 ql/csharp/ql/src/Documentation/XmldocMissingReturn.ql

csharp/ql/src/Documentation/XmldocMissing.ql

@@ -6,8 +6,7 @@
  * @problem.severity recommendation
  * @precision medium
  * @id cs/xmldoc/missing-xmldoc
- * @tags quality
- *       maintainability
+ * @tags maintainability
  *       readability
  */