fix: guard against KeyError (#8485)

Author: jennifer-richards

ietf/iesg/utils.py

@@ -33,7 +33,7 @@ def telechat_page_count(date=None, docs=None, ad=None):
             ballot = draft.active_ballot()
             if ballot:
                 positions = ballot.active_balloter_positions()
-                ad_position = positions[ad]
+                ad_position = positions.get(ad, None)
                 if ad_position is None or ad_position.pos_id == "norecord":
                     ad_pages_left_to_ballot_on += draft.pages or 0