docs/cli: Fix sphinx warning

Related to T2265

docs/cli.rst

@@ -13,7 +13,7 @@ Shared command-line interface
 Database initialization utilities
 ---------------------------------
 
-.. click:: swh.core.cli.db:init
+.. click:: swh.core.cli.db:db_init
   :prog: swh db init
   :nested: full
 

[Phabricator Migration user]

Some references in the commit message have been migrated:

• T2265 is now swh-docs#2265 (closed)