8cf9898b53 qt: Change default size of intro frame (Emil Engler)
Pull request description:
Because of the new pruning feature in the intro frame, the size of the intro frame is too small.
Like you see, some text is not visible completely.
### Before

### After

Update: I changed it so it adjusts the size dynamically
ACKs for top commit:
fanquake:
ACK 8cf9898b53 - Before and after macOS screens below. Given that most users will only ever see this screen once, I think Qts best effort to dynamically size it is fine.
jonasschnelli:
utACK 8cf9898b53
Sjors:
Tested ACK 8cf9898 on macOS. English already fit, so to reproduce the issue, launch in German with `-resetguisettings -lang=de`.
laanwj:
ACK 8cf9898b53
Tree-SHA512: 568b0ae0d5feeda603c0ccf67b5bb3857becea8f22fb98695e1901e662cb1e76377589e39ec743258154d7f6c4a5e544bb003fcc73597400dd427db047392638