curl tool: don't abort glob-loop due to failures

We want to continue to the next URL to try even on failures returned
from libcurl. This makes -f with ranges still get subsequent URLs even
if occasional ones return error. This was a regression as it used to
work and broke in the 7.23.0 release.

Added test case 1328 to verify the fix.

Bug: http://curl.haxx.se/bug/view.cgi?id=3481223
Reported by: Juan Barreto