fixed struct alignment && refactor linter (#369)

## Pull Request template
Please, go through these steps before clicking submit on this PR.

1. Give a descriptive title to your PR.
2. Provide a description of your changes.
3. Make sure you have some relevant tests.
4. Put `closes #XXXX` in your comment to auto-close the issue that your PR fixes (if applicable).

**PLEASE REMOVE THIS TEMPLATE BEFORE SUBMITTING**

Reviewed-on: #369
Co-authored-by: Evstigneev Denis <danteevstigneev@yandex.ru>
Co-committed-by: Evstigneev Denis <danteevstigneev@yandex.ru>

server/server.go

@@ -12,7 +12,7 @@ import (
 
 // DefaultServer default server
 var (
-	DefaultServer Server = NewServer()
+	DefaultServer = NewServer()
 )
 
 var (