[IT-1681] Restore asset-pipeline default version
[IT-1681] Restore asset-pipeline default version

I am reverting part of my commit 9d8d291 with the commit comment
"First executable OSM with Grails 3.2". There was no need to specify
the asset-pipeline version explicitly.

iteratec/OpenSpeedMonitor,IteraSpeed/OpenSpeedMonitor,iteratec/OpenSpeedMonitor,IteraSpeed/OpenSpeedMonitor,IteraSpeed/OpenSpeedMonitor,iteratec/OpenSpeedMonitor,iteratec/OpenSpeedMonitor,iteratec/OpenSpeedMonitor