[MM-62179] Fix: mmctl debug error when setting email (#29953)

* only GetUserByEmail if arg is an email

* fixing tests

* fix typo

server/cmd/mmctl/commands/userargs_test.go

@@ -18,11 +18,6 @@ func (s *MmctlUnitTestSuite) TestGetUserFromArgs() {
 		notFoundEmail := "emailNotfound@notfound.com"
 		notFoundErr := errors.New("user not found")
 		printer.Clean()
-		s.client.
-			EXPECT().
-			GetUserByEmail(context.TODO(), notFoundEmail, "").
-			Return(nil, &model.Response{StatusCode: http.StatusNotFound}, notFoundErr).
-			Times(1)
 		s.client.
 			EXPECT().
 			GetUserByUsername(context.TODO(), notFoundEmail, "").