fix build warnings on v4.2

Author: jeff-allen-mongo

conf.py

@@ -101,6 +101,7 @@ def has(self, *args):
     'mms-home': ('https://www.mongodb.com/cloud/cloud-manager%s', ''),
     'opsmgr': ('https://docs.opsmanager.mongodb.com/current%s', ''),
     'atlas': ('https://docs.atlas.mongodb.com%s',''),
+    'compass': ('https://docs.mongodb.com/compass/current%s', ''),
     'products': ('https://www.mongodb.com/products%s', ''),
     'wtdocs': ('https://source.wiredtiger.com/mongodb-3.4%s', ''),
     'perl-api': ('https://metacpan.org/pod/MongoDB::%s', ''),