Bug fix: CompositionProxyTypeBuilder crashed when class has protected constructor.

test/Spring/Spring.Core.Tests/Objects/ClassWithProtectedCtor.cs

@@ -0,0 +1,13 @@
+namespace Spring.Objects
+{
+    public class ClassWithProtectedCtor : IOther
+    {
+        protected ClassWithProtectedCtor()
+        {
+        }
+
+        public void Absquatulate()
+        {                
+        }
+    }
+}