refuse to run on qt 5.10

- on Linux and Windows, opening the browser and stats window back and
forth multiple times triggers a crash in the GL libraries, even with
software rendering enabled. Will try again when .1 is out
- on Mac, shortcut keys fire multiple times:
https://bugreports.qt.io/browse/QTBUG-65184

aqt/qt.py

@@ -40,3 +40,5 @@ qtpoint = QT_VERSION & 0xff
 
 if qtmajor < 5 or (qtmajor == 5 and qtminor < 9):
     raise Exception("Anki requires Qt 5.9.0+")
+if qtmajor == 5 and qtminor == 10:
+    raise Exception("Qt 5.10 is known to be buggy.")