Request #5941: Cannot import a field which is defined as Multi-Select

Change-Id: Ib260bef50e05383f875a983d3ba265ea120bb91c
Merge commit 'refs/changes/76/1776/2' of ssh://gerrit.tuleap.net:29418/tuleap into stable

* ssh://gerrit.tuleap.net:29418/tuleap:
  Request #5941: Cannot import a field which is defined as Multi-Select

Change-Id: I985c01fc3778ced325424e2efab4ade77787c1da
This is Tuleap 6.9.99.35

Change-Id: I359a266fbce25507010bbb6aa32f05ea86fdbeae