The dns_request_createraw() function, unlike dns_request_create(), when
calculating the UDP timeout value, doesn't check that 'udpretries' is
not zero, and that is the more logical behavior, because the calculation
formula uses division to 'udpretries + 1', where '1' is the first try.
Change the dns_request_create() function to remove the 'udpretries != 0'
condition.
Add a 'REQUIRE(udpretries != UINT_MAX)' check to protect from a division
by zero.
Make the 'request->udpcount' field to represent the number of tries,
instead of the number of retries.