euscanwww: adding elem.clear() to prevent memory leaking in xml parsing

Signed-off-by: volpino <fox91@anche.no>

euscanwww/djeuscan/processing/scan_portage.py

@@ -141,6 +141,7 @@ class ScanPortage(object):
                 if elem.tag == "category":
                     # clean old data
                     cat = ""
+            elem.clear()
 
         if self.purge_packages:
             for package in current_packages: