Trim trailing slashes when matching URLs (#910)

This is another bit of Browsertrix normalization I missed in #909. Makes WARC import a little more stable and reliable.

Author: Mr0grog

web_monitoring/utils.py

@@ -231,7 +231,7 @@ def matchable_url(url: str) -> str:
     parsed = urlsplit(url)
     return parsed._replace(
         netloc=normalize_netloc(parsed),
-        path=(parsed.path or '/'),
+        path=(parsed.path or '/').rstrip('/'),
         query=matchable_querystring(parsed.query),
         fragment=''
     ).geturl()