Sorry, misread installation instead of upgrade... (I'm working and I couldn't read carefully... )
Right, the upgrade stops without allowing to continue.
Please open the file "installcore.php" that you find in the install directory, then change:
const CURRENT_VERSION = '1.1.4';
to:
const CURRENT_VERSION = '1.1.5';
...and to stay on the safe side change also:
* @version 1.1.4
into:
* @version 1.1.5
it should affect the upgrade, but while the file is open, it's easier.