This reverts commit a2a319ee.

Reason for revert: We wanted to make the protocol decision dynamic
after all, based on the configured server URL. With the previous
behavior the users are required to build a separate set of binaries,
even if they want to just quickly evaluate or test the license
server using plain HTTP.

Pick-to: 3.1
Task-number: QLS-957
Change-Id: I7a726c1b32afd6aa1a8f130392ba0a0f1d4416c5
Reviewed-by: Iikka Eklund <iikka.eklund@qt.io>