Keep py3.X compatibility for urllib

Change-Id: Iba10637688ada66f2e3003cd87bbba7d4db4abc7
Closes-Bug: #1280105
diff --git a/tools/find_stack_traces.py b/tools/find_stack_traces.py
index 49a42fe..f2da27a 100755
--- a/tools/find_stack_traces.py
+++ b/tools/find_stack_traces.py
@@ -19,8 +19,8 @@
 import pprint
 import re
 import six
+import six.moves.urllib.request as urlreq
 import sys
-import urllib2
 
 
 pp = pprint.PrettyPrinter()
@@ -65,9 +65,9 @@
 
 def hunt_for_stacktrace(url):
     """Return TRACE or ERROR lines out of logs."""
-    req = urllib2.Request(url)
+    req = urlreq.Request(url)
     req.add_header('Accept-Encoding', 'gzip')
-    page = urllib2.urlopen(req)
+    page = urlreq.urlopen(req)
     buf = six.StringIO(page.read())
     f = gzip.GzipFile(fileobj=buf)
     content = f.read()
@@ -105,7 +105,7 @@
 
 
 def collect_logs(url):
-    page = urllib2.urlopen(url)
+    page = urlreq.urlopen(url)
     content = page.read()
     logs = re.findall('(screen-[\w-]+\.txt\.gz)</a>', content)
     return logs