修复 VirtualMethodGroupCalculator 计算一个类型继承了多个interface，并且这些interface包含相同签名的函数时，未映射为相同虚函数名的bug

Editor/ObfusPasses/SymbolObfus/VirtualMethodGroupCalculator.cs

@@ -117,9 +117,9 @@ namespace Obfuz.ObfusPasses.SymbolObfus
                         }
                     }
                 }
+                typeMethods.flatMethods.Add(method);
             }
 
-            typeMethods.flatMethods.AddRange(interfaceMethods);
             foreach (MethodDef method in typeDef.Methods)
             {
                 if (!method.IsVirtual)