Updated BlocksModule version to 3.9.0

This makes room for minor fixes in the Zikula Core 1.3.x branch for Blocks.
Yes in 1.3.8.
I want to make a 3.8.2 in the 1.3.x branch and add the HookUtil there, just like is done here in the Installer. So 3.8.2 will have hooks already and don't need the upgrade. Otherwise HTMLBlocks don't work with Scribite 5 in 1.3.x