Fix for public constructor on messages
diff --git a/src/AddressBook/AddressBookProtos.cs b/src/AddressBook/AddressBookProtos.cs
index cb8a2d9..9b99452 100644
--- a/src/AddressBook/AddressBookProtos.cs
+++ b/src/AddressBook/AddressBookProtos.cs
@@ -68,6 +68,7 @@
   [global::System.Runtime.CompilerServices.CompilerGeneratedAttribute()]

   [global::System.CodeDom.Compiler.GeneratedCodeAttribute("ProtoGen", "2.3.0.277")]

   public sealed partial class Person : pb::GeneratedMessage<Person, Person.Builder> {

+    private Person() { }

     private static readonly Person defaultInstance = new Builder().BuildPartial();

     private static readonly string[] _personFieldNames = new string[] { "email", "id", "name", "phone" };

     private static readonly uint[] _personFieldTags = new uint[] { 26, 16, 10, 34 };

@@ -108,6 +109,7 @@
       [global::System.Runtime.CompilerServices.CompilerGeneratedAttribute()]

       [global::System.CodeDom.Compiler.GeneratedCodeAttribute("ProtoGen", "2.3.0.277")]

       public sealed partial class PhoneNumber : pb::GeneratedMessage<PhoneNumber, PhoneNumber.Builder> {

+        private PhoneNumber() { }

         private static readonly PhoneNumber defaultInstance = new Builder().BuildPartial();

         private static readonly string[] _phoneNumberFieldNames = new string[] { "number", "type" };

         private static readonly uint[] _phoneNumberFieldTags = new uint[] { 10, 16 };

@@ -766,6 +768,7 @@
   [global::System.Runtime.CompilerServices.CompilerGeneratedAttribute()]

   [global::System.CodeDom.Compiler.GeneratedCodeAttribute("ProtoGen", "2.3.0.277")]

   public sealed partial class AddressBook : pb::GeneratedMessage<AddressBook, AddressBook.Builder> {

+    private AddressBook() { }

     private static readonly AddressBook defaultInstance = new Builder().BuildPartial();

     private static readonly string[] _addressBookFieldNames = new string[] { "person" };

     private static readonly uint[] _addressBookFieldTags = new uint[] { 10 };