Fix potential crash by removing an unnecessary column.

The column I removed is already in the recipient half of the projection.
Having two representations of the groupId made reading the groupId out
of the cursor non-deterministic, and when compounded with another bug,
could cause a crash if one of them was null.

app/src/main/java/org/thoughtcrime/securesms/database/RecipientDatabase.java

@@ -760,8 +760,7 @@ private List<RecipientSettings> getRecipientSettingsForSync(@Nullable String que
     List<RecipientSettings> out   = new ArrayList<>();
 
     String[] columns = ArrayUtils.concat(RECIPIENT_FULL_PROJECTION,
-      new String[]{ GroupDatabase.TABLE_NAME + "." + GroupDatabase.GROUP_ID,
-                    GroupDatabase.TABLE_NAME + "." + GroupDatabase.V2_MASTER_KEY });
+      new String[]{GroupDatabase.TABLE_NAME + "." + GroupDatabase.V2_MASTER_KEY });
 
     try (Cursor cursor = db.query(table, columns, query, args, null, null, null)) {
       while (cursor != null && cursor.moveToNext()) {