prevent the plug-in updater from going off screen

Another quickie for 1.2.0

One way to test is to downgrade all plug-ins. Here’s a script that will do it.

```python
#!/usr/bin/env python

import os
from plistlib import readPlist, writePlist

plugin_path = '/path/to/copy/of/PlugIns'
for fitem in os.listdir(plugin_path):
    if fitem.endswith('.qsplugin'):
        plist_path_parts = [plugin_path, fitem, 'Contents', 'Info.plist']
        plist_path = '/'.join(plist_path_parts)
        data = readPlist(plist_path)
        current_version = data['CFBundleVersion']
        version = hex(int(current_version, 16) - 1)[2:]
        data['CFBundleVersion'] = version.upper()
        writePlist(data, plist_path)
```