Fix for gevent as optional

cps.py

@@ -20,10 +20,11 @@ if __name__ == '__main__':
     if web.ub.DEVELOPMENT:
         web.app.run(host="0.0.0.0", port=web.ub.config.config_port, debug=True)
     else:
-        if len(sys.argv) > 1 and sys.argv[1] == '-g':
-            http_server = WSGIServer(('', web.ub.config.config_port), web.app)
-            http_server.serve_forever()
-        else:
+        try:
+            web.app.logger.info('Attempting to start gevent')
+            web.start_gevent()
+        except ImportError:
+            web.app.logger.info('Falling back to Tornado')
             http_server = HTTPServer(WSGIContainer(web.app))
             http_server.listen(web.ub.config.config_port)
             IOLoop.instance().start()

cps/ub.py

@@ -315,7 +315,7 @@ class Config:
         else:
             self.config_google_drive_watch_changes_response=None
         self.config_columns_to_ignore = data.config_columns_to_ignore
-        if (self.config_calibre_dir is not None and not self.config_use_google_drive) or os.path.exists(self.config_calibre_dir + '/metadata.db'):
+        if self.config_calibre_dir is not None and (not self.config_use_google_drive or os.path.exists(self.config_calibre_dir + '/metadata.db')):
             self.db_configured = True
         else:
             self.db_configured = False