Sanitize RemoteEmail user prop (#27170)

* Sanitize RemoteEmail user prop

If the server is configured to hide user emails, the "RemoteEmail"
user property will be sanitized as well, effectively hiding the real
email of remote users.

* fix merge conflict

---------

Co-authored-by: Doug Lauder <wiggin77@warpmail.net>
Co-authored-by: Mattermost Build <build@mattermost.com>

server/public/model/user_test.go

@@ -384,3 +384,22 @@ func TestValidateCustomStatus(t *testing.T) {
 		assert.True(t, user0.ValidateCustomStatus())
 	})
 }
+
+func TestSanitizeProfile(t *testing.T) {
+	t.Run("should correctly sanitize email and remote email", func(t *testing.T) {
+		user := &User{
+			Email: "john@doe.com",
+			Props: StringMap{UserPropsKeyRemoteEmail: "remote@doe.com"},
+		}
+
+		user.SanitizeProfile(nil)
+
+		require.Equal(t, "john@doe.com", user.Email)
+		require.Equal(t, "remote@doe.com", user.Props[UserPropsKeyRemoteEmail])
+
+		user.SanitizeProfile(map[string]bool{"email": false})
+
+		require.Empty(t, user.Email)
+		require.Empty(t, user.Props[UserPropsKeyRemoteEmail])
+	})
+}