presence: Check away status first in getPresenceStatusForUserId

Not NFC, in that if the user is away but we lack presence data for
them, this will switch from returning null to returning "unavailable".
But I don't really have a clear preference which of those two happens,
particularly as the "away status" concept is obsolete.

Author: gnprice

src/presence/presenceModel.js

@@ -172,6 +172,12 @@ export const getPresenceStatusForUserId = (
   state: PerAccountState,
   userId: UserId,
 ): PresenceStatus | 'unavailable' | null => {
+  // TODO(server-6.0): Cut this; UserStatus['away'] was replaced by "invisible mode".
+  //   https://chat.zulip.org/#narrow/stream/2-general/topic/.22unavailable.22.20status/near/1454779
+  if (getZulipFeatureLevel(state) < 148 && getUserStatus(state, userId).away) {
+    return 'unavailable';
+  }
+
   const presence = getPresence(state);
   const user = tryGetUserForId(state, userId);
   if (!user) {
@@ -182,12 +188,6 @@ export const getPresenceStatusForUserId = (
     return null;
   }
 
-  // TODO(server-6.0): Cut this; UserStatus['away'] was replaced by "invisible mode".
-  //   https://chat.zulip.org/#narrow/stream/2-general/topic/.22unavailable.22.20status/near/1454779
-  if (getZulipFeatureLevel(state) < 148 && getUserStatus(state, userId).away) {
-    return 'unavailable';
-  }
-
   return statusFromPresence(userPresence);
 };