Update clean-database to drop additional tables

Updates clean-database.sql file to drop tables recently added to the
DSpace project:

-  webapp, webapp_seq
- requestitem, requestitem_seq;
DS-1998 fix the "dspace classpath" CLI command
DS-1958 Fix SolrLogger Memory Error
Language Selection _ Turkish Option
[DS-1961] Use HTTPS with oss.sonatype.org repository
Updated bte dependence to v0.9.2.4

See the relevant discussion here: https://jira.duraspace.org/browse/DS-1971
DS-2013 implement ItemDAOOracle to fix thumbnails in browse
Add Hello World curation task