[IMPR] reduce code complexity of pagegenerators.py

Change-Id: I135fb03c04c4ea797f61dc5da891c8eb62856c7f
---
M pywikibot/pagegenerators.py
1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/pywikibot/pagegenerators.py b/pywikibot/pagegenerators.py
index 2af367f..3bae2b5 100644
--- a/pywikibot/pagegenerators.py
+++ b/pywikibot/pagegenerators.py
@@ -1939,12 +1939,11 @@
         max_revision_depth
     @param show_filtered: Output a message for each page not yielded
     """
-    ts = None
-    if timestamp:
-        if isinstance(timestamp, str):
-            ts = pywikibot.Timestamp.fromtimestampformat(timestamp)
-        else:
-            ts = timestamp
+    if isinstance(timestamp, str):
+        ts = pywikibot.Timestamp.fromtimestampformat(timestamp)
+    else:
+        ts = timestamp
+
     for page in generator:
         contribs = page.contributors(total=max_revision_depth, endtime=ts)
         if bool(contribs[username]) is not bool(skip):  # xor operation

