When a forwarder fails and we're not in a forward-only mode we

When a forwarder fails and we're not in a forward-only mode we
go back to regular resolution. When this happens the fetch timer is
already running, and we might end up in a situation where we we create
a fetch for qname-minimized query and after that the timer is triggered
and the query is retried (fctx_try) - which causes relaunching of
qname-minimization fetch - and since we already have a qmin fetch
for this fctx - assertion failure.

This fix stops the timer when doing qname minimization - qmin fetch
internal timer should take care of all the possible timeouts.