MM-19310 - Wrong validation message when Bot name ends in a . (#12905)

* MM-19310 - Wrong validation message when Bot name ends in a .

* Reverting back old behaviour

app/bot_test.go

@@ -45,6 +45,20 @@ func TestCreateBot(t *testing.T) {
 			require.NotNil(t, err)
 			require.Equal(t, "model.bot.is_valid.description.app_error", err.Id)
 		})
+
+		t.Run("username contains . character", func(t *testing.T) {
+			th := Setup(t).InitBasic()
+			defer th.TearDown()
+
+			bot, err := th.App.CreateBot(&model.Bot{
+				Username:    "username.",
+				Description: "a bot",
+				OwnerId:     th.BasicUser.Id,
+			})
+			require.NotNil(t, err)
+			require.Nil(t, bot)
+			require.Equal(t, "model.user.is_valid.email.app_error", err.Id)
+		})
 	})
 
 	t.Run("create bot", func(t *testing.T) {