修复bak文件重复时，before类型执行不成功的问题

Program.cs

@@ -106,10 +106,10 @@ namespace NetGitTool
                         content = reader.ReadToEnd();
                     }
                     var bakfile = file + ".bak";
-                    //if (File.Exists(bakfile))
-                    //{
-                    //    File.Delete(bakfile);
-                    //}
+                    if (File.Exists(bakfile))
+                    {
+                        File.Delete(bakfile);
+                    }
                     File.Move(file, bakfile);
                     Regex regex = new Regex("AssemblyFileVersion\\(\".*\"\\)");
                     content = regex.Replace(content, string.Format("AssemblyFileVersion(\"{0}\")", versionName));