Fixed the system module linking itself when auto-compiling.

Signed-off-by: Dimitar Dobrev <dpldobrev@protonmail.com>

src/Generator/Driver.cs

@@ -434,6 +434,7 @@ namespace CppSharp
                     CompilerOptions = compilerOptions.ToString()
                 };
 
+            if (module != AST.Module.SystemModule)
                 compilerParameters.ReferencedAssemblies.Add(
                     string.Format("{0}.dll", AST.Module.SystemModule.LibraryName));
             // add a reference to System.Core