Fix expired build URLs in RPM unit tests

Some example URLs in the packaging unit tests have expired, need to be updated.

```

-----> Running tox pkg_unittests
.........EE.......................................
======================================================================
ERROR: test_nitrogen_autorelease_url (packages.test_lib.TestExtractVersion)
Test URL of an ODL Nitrogen autorelease build.
----------------------------------------------------------------------
Traceback (most recent call last):
File "packages/test_lib.py", line 125, in test_nitrogen_autorelease_url
version = lib.extract_version(url)
File "packages/lib.py", line 70, in extract_version
version = extract_autorelease_version(url, version)
File "packages/lib.py", line 141, in extract_autorelease_version
build_date = datetime.datetime.strptime(raw_date, "%d %b %Y").strftime(
File "/usr/lib64/python2.7/_strptime.py", line 325, in _strptime
(data_string, format))
ValueError: time data '' does not match format '%d %b %Y'

======================================================================
ERROR: test_nitrogen_autorelease_zip_url (packages.test_lib.TestExtractVersion)
Test URL of an ODL Nitrogen autorelease build zip archive.
----------------------------------------------------------------------
Traceback (most recent call last):
File "packages/test_lib.py", line 135, in test_nitrogen_autorelease_zip_url
version = lib.extract_version(url)
File "packages/lib.py", line 70, in extract_version
version = extract_autorelease_version(url, version)
File "packages/lib.py", line 141, in extract_autorelease_version
build_date = datetime.datetime.strptime(raw_date, "%d %b %Y").strftime(
File "/usr/lib64/python2.7/_strptime.py", line 325, in _strptime
(data_string, format))
ValueError: time data '' does not match format '%d %b %Y'

----------------------------------------------------------------------
Ran 50 tests in 3.644s

FAILED (errors=2)

```

https://logs.opendaylight.org/releng/jenkins092/packaging-tox-verify-oxygen/14/console.log.gz