try other servers when receiving FORMERR
previously, when an iterative query returned FORMERR, resolution would be stopped under the assumption that other servers for the same domain would likely have the same capabilities. this assumption is not correct; some domains have been reported for which some but not all servers will return FORMERR to a given query. trying the other servers allows recursion to succeed.
Closes #3152 (closed)
Edited by Evan Hunt