OPENTOK-17941 #comment Because... when a configuration change happens, t...

...he subscriberview removal is immediate, and the subscriberview re-addition is delayed... it's possible to have remove/remove/add/add ordering instead of remove/add/remove/add when two config changes happen quickly (which seems to be possible when iOS is on the other side of the connection).  You add twice in a row, you crash.  So we'll do a harmless (hopefully) redundant remove before we re-add the subscriber view
@marinaserranomontes Yes, but the problem is you are removing the view synchronously (immediately) and reloadInterface adds the view again asynchronously (later).  If you get two onConfigurationChanged quickly enough, you can end up doing remove/remove/add/add, i.e. you do both of your synchronous removes immediately *before* either of the asynchronous adds happen.  It will crash on the second add, which was the bug.