default shared history vis on unknown visibilities, drop needless error log

Signed-off-by: June Clementine Strawberry <june@3.dog>

src/service/rooms/state_accessor/server_can.rs

@@ -50,8 +50,8 @@ pub async fn server_can_see_event(
 				.await
 		},
 		| _ => {
-			error!("Unknown history visibility {history_visibility}");
-			false
+			debug_info!(%room_id, "Unknown history visibility, defaulting to shared: {history_visibility:?}");
+			true
 		},
 	}
 }

src/service/rooms/state_accessor/user_can.rs

@@ -119,8 +119,8 @@ pub async fn user_can_see_event(
 			self.user_was_joined(shortstatehash, user_id).await
 		},
 		| _ => {
-			error!("Unknown history visibility {history_visibility}");
-			false
+			debug_info!(%room_id, "Unknown history visibility, defaulting to shared: {history_visibility:?}");
+			currently_member
 		},
 	}
 }