Reverts third_party/protobuf: Update to HEAD (f52e188fe4)

third_party/protobuf/csharp/src/AddressBook/project.json

Index: third_party/protobuf/csharp/src/AddressBook/project.json
diff --git a/third_party/protobuf/csharp/src/AddressBook/project.json b/third_party/protobuf/csharp/src/AddressBook/project.json
deleted file mode 100644
index c500bdc29654ede70525de2803027a0eed429ad2..0000000000000000000000000000000000000000
--- a/third_party/protobuf/csharp/src/AddressBook/project.json
+++ /dev/null
@@ -1,20 +0,0 @@
-{
-  "buildOptions": {
-    "debugType": "portable",
-    "emitEntryPoint": true,
-    "additionalArguments": [ "/main:Google.Protobuf.Examples.AddressBook.Program" ]
-  },
-  "dependencies": {
-    "Google.Protobuf": { "target": "project" }
-  },
-  "frameworks": {
-    "netcoreapp1.0": {
-      "dependencies": {
-        "Microsoft.NETCore.App": {
-          "type": "platform",
-          "version": "1.0.0"
-        }
-      }
-    }
-  }
-}