Fix build

src/DMAPI/tgs.dm

@@ -100,7 +100,7 @@
 	var/connection_name		//the name of the configured chat connection
 	var/is_admin_channel	//if the server operator has marked this channel for game admins only
 	var/is_private_channel	//if this is a private chat channel
-	var/tag					//user defined string associated with channel
+	var/custom_tag					//user defined string associated with channel
 
 //represents a chat user
 /datum/tgs_chat_user

src/DMAPI/tgs/v4/api.dm

@@ -292,7 +292,7 @@
 	channel.connection_name = channel_json["connectionName"]
 	channel.is_admin_channel = channel_json["isAdminChannel"]
 	channel.is_private_channel = channel_json["isPrivateChannel"]
-	channel.tag = channel_json["tag"]
+	channel.custom_tag = channel_json["tag"]
 	return channel
 
 /*

tests/Tgstation.Server.Api.Tests/TestApiHeaders.cs

@@ -0,0 +1,23 @@
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using System;
+using System.Net.Http.Headers;
+
+namespace Tgstation.Server.Api.Tests
+{
+	/// <summary>
+	/// Tests for <see cref="ApiHeaders"/>
+	/// </summary>
+	[TestClass]
+	public sealed class TestApiHeaders
+	{
+		readonly ProductHeaderValue productHeaderValue = new ProductHeaderValue("Tgstation.Server.Api.Tests", "1.0.0");
+
+		[TestMethod]
+		public void TestConstruction()
+		{
+			Assert.ThrowsException<ArgumentNullException>(() => new ApiHeaders(null, null));
+			Assert.ThrowsException<ArgumentNullException>(() => new ApiHeaders(productHeaderValue, null));
+			var headers = new ApiHeaders(productHeaderValue, String.Empty);
+		}
+	}
+}