Update xrootd to version 4.5.0

[cmsbuild]

backport of #2648

[cmsbuild]

A new Pull Request was created by @cmsbuild for branch IB/CMSSW_7_6_X/stable.

@cmsbuild, @smuzaffar, @iahmad-khan, @davidlange6 can you please review it and eventually sign? Thanks.
You can sign-off by replying to this message having '+1' in the first line of your reply.
You can reject by replying to this message having '-1' in the first line of your reply.

[smuzaffar]

please test

[cmsbuild]

The tests are being triggered in jenkins.
https://cmssdt.cern.ch/jenkins/job/cmsdist-test-pr/452/console

[cmsbuild]

-1

Tested at: 21d8d79

You can see the results of the tests here:
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-2734/452/summary.html

I found follow errors while testing this PR

Failed tests: UnitTests

• Unit Tests:

I found errors in the following unit tests:

---> test testTechnologyPlugin had ERRORS

[cmsbuild]

Comparison job queued.

[cmsbuild]

Comparison is ready
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-2734/452/summary.html

[smuzaffar]

+externals
test failed due to

DecodingKey::init: Required Key File "/afs/cern.ch/cms/DB/conddb/.cms_cond/db.key" is missing or unreadable. 

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next IB/CMSSW_7_6_X/stable IBs (but tests are reportedly failing). This pull request requires discussion in the ORP meeting before it's merged. @slava77, @davidlange6, @smuzaffar