xrootd: split protocol name form the client IP in XrootdProtocolInfo

Acked-by: Paul Millar
Target: master, 2.8, 2.9
Require-book: no
Require-notes: yes
(cherry picked from commit 0eb1af0b1c867fe736220ba1dbbf581232c4aefc)
Signed-off-by: Tigran Mkrtchyan <tigran.mkrtchyan@desy.de>
Merge pull request #567 from kofemann/fix-proto-2.9

xrootd: split protocol name form the client IP in XrootdProtocolInfo