Hey Sergey,
I am really sorry for the delay of this reply as it is actually a public day off for us here. I have checked your site and it looks like there is something wrong with the "External URL" menu type in Joomla for some reasons which causes the redirection issue.
A temporary workaround that I have performed for your site is to change the menu type for the menu "Соцсеть" so that it uses the alias menu type instead,
http://take.ms/1nTiV since you are actually linking to your own menu item.
Once you have chosen the alias menu type in Joomla, you could just pick the "Community" menu item,
http://take.ms/7NVSh and then save the menu item,
http://take.ms/3Dkoq
I have created a ticket internally to check on the JRoute issues with external urls.