Remove warning about incompatibility of null and string

Author: tripolkaandrey

_config.yml

@@ -1,7 +1,7 @@
 title: Spine Event Engine
 description: CQRS/ES framework for modern could applications
 
-baseurl:
+baseurl: ""
 
 githuburl: https://github.com/SpineEventEngine/SpineEventEngine.github.io/
 core_java_repo: https://github.com/SpineEventEngine/core-java