fix(session-keywords): close sessions instead of delete references

Author: gtoselli

src/RequestsLibrary/SessionKeywords.py

@@ -545,7 +545,7 @@ def delete_all_sessions(self):
         """ Removes all the session objects """
         logger.info('Deleting All Sessions')
 
-        self._cache.empty_cache()
+        self._cache.close_all()
 
     # TODO this is not covered by any tests
     @keyword("Update Session")