BUG: Fixed application information logging

displayApplicationInformations() was called in qSlicerApplication before initializing the logging.
Therefore the application information (that is essential for troubleshooting) was not included in the application log.

git-svn-id: http://svn.slicer.org/Slicer4/trunk@24270 3bd1e089-480b-0410-8dfb-8563597acbee