Removed BarotraumaServer's MonoGame dependency

BarotraumaServer/Source/Physics/PhysicsBody.cs

@@ -0,0 +1,15 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace Barotrauma
+{
+    partial class PhysicsBody
+    {
+        private void DisposeProjSpecific()
+        {
+            //do nothing
+        }
+    }
+}