Fix size of ProjectDialog used by PLCOpenEditor

Disable scrolling for ProjectDialog, because otherwise very very small
windows is created.
This regression was introduced by 5701225 ("replaced normal panel with scrolled panel under project
properties").

[TOPOLOGY]
NetName=None
Nodes=0x01
Node2Present=0x01
Node2Name=SlaveNode
Node2DCFName=Slave_0_0.eds
EDSBaseName=eds