Change: Remove handling of draft change status

This handling was needed for sites that have not yet migrated to
a version where draft change support was removed, i.e. 2.16 and
later.

It is expected that any site upgrading to 3.1 will be doing so
from 3.0, not directly from pre 2.16, so this can now be removed.

Change-Id: I48d87fc3bc7024204352ffb44017ba93c8bda97b

java/com/google/gerrit/reviewdb/client/Change.java

@@ -426,13 +426,6 @@ public final class Change {
         }
       }
 
-      // TODO(davido): Remove in 3.0, after all sites upgraded to version,
-      // where DRAFT status was removed. This code path is still needed,
-      // when changes are deserialized from the secondary index, during
-      // the online migration to the new schema version wasn't completed.
-      if (c == 'd') {
-        return Status.NEW;
-      }
       return null;
     }