deployqtHelper_mac.sh: Fix incorrect merge

This fixes 522033d (Add a plugin for Mer). It seems during rebase to 2.8
part of 71f1919 (Mac: Deploy and patch qml imports and qml2puppet) was
lost - substitution of $designerPluginArguments with
$qml2puppetArgument.

Signed-off-by: Martin Kampas <martin.kampas@jolla.com>
Fix licence header

Introduced with 57be116 (Jolla: Add SailfishOS specific welcome page) -
unintentionally edited qtcreator's own gettingstarted.qml instead of the
one owned by mer plugin which was derived from it.

Signed-off-by: Martin Kampas <martin.kampas@jolla.com>