The webapi schema was created from the value specified in your settings.xml file:
<datasource.ohdsi.schema>webapi</datasource.ohdsi.schema>
There’s no problem with having the WebAPI tables created in that schema, just don’t move them manually. In the future as you install new versions of webAPI, the database will be automatically updated to support the new version of WebAPI. If you move the tables to another schema, however, the system won’t know they moved, and you have problems.
-Chris