update Makefile.am

Makefile.am

@@ -78,6 +78,7 @@ csharp_EXTRA_DIST=                                                           \
   csharp/protos/unittest_import.proto                                        \
   csharp/protos/unittest_issues.proto                                        \
   csharp/protos/unittest_proto3.proto                                        \
+  csharp/protos/unittest_selfreferential_options.proto                       \
   csharp/protos/unittest.proto                                               \
   csharp/src/AddressBook/AddPerson.cs                                        \
   csharp/src/AddressBook/Addressbook.cs                                      \
@@ -153,6 +154,7 @@ csharp_EXTRA_DIST=                                                           \
   csharp/src/Google.Protobuf.Test.TestProtos/UnittestIssues.cs                  \
   csharp/src/Google.Protobuf.Test.TestProtos/UnittestProto3.cs                  \
   csharp/src/Google.Protobuf.Test.TestProtos/UnittestProto3Optional.cs          \
+  csharp/src/Google.Protobuf.Test.TestProtos/UnittestSelfreferentialOptions.cs  \
   csharp/src/Google.Protobuf.Test.TestProtos/UnittestWellKnownTypes.cs          \
   csharp/src/Google.Protobuf.Test.TestProtos/Unittest.cs                        \
   csharp/src/Google.Protobuf.Test/WellKnownTypes/AnyTest.cs                  \