XWIKI-11477: Failed to access wiki when the descriptor is not stored in the object number 0 of the document

Conflicts:
	xwiki-platform-core/xwiki-platform-wiki/xwiki-platform-wiki-default/pom.xml
	xwiki-platform-core/xwiki-platform-wiki/xwiki-platform-wiki-default/src/main/java/org/xwiki/wiki/internal/descriptor/builder/DefaultWikiDescriptorBuilder.java
	xwiki-platform-core/xwiki-platform-wiki/xwiki-platform-wiki-default/src/test/java/org/xwiki/wiki/internal/descriptor/builder/DefaultWikiDescriptorBuilderTest.java