Updated BlocksModule version to 3.9.0

This makes room for minor fixes in the Zikula Core 1.3.x branch for Blocks.
[Blocks] Added new versionnr 3.9.0 to Installer 

Nothin to be done for this update. This small update in version nr makes room for minor fixes in the Blocks 1.3.x branch of the Core.
Merge pull request #1741 from espaan/patch-9

Updated BlocksModule version to 3.9.0