only focus webview after fields have been set

on some platforms the old approach was causing a focus+blur event to
fire with the old note contents

fixes

https://anki.tenderapp.com/discussions/beta-testing/681-red-cloze

and probably fixes

https://anki.tenderapp.com/discussions/beta-testing/683-back-input-returns

aqt/editor.py

@@ -264,11 +264,10 @@ class Editor:
                 return
             self.setupForegroundButton()
             self.checkValid()
+            if focusTo is not None:
+                self.web.setFocus()
             runHook("loadNote", self)
 
-        if focusTo is not None:
-            self.web.setFocus()
-
         self.web.evalWithCallback("setFields(%s, %s); setFonts(%s); focusField(%s)" % (
             json.dumps(data), json.dumps(self.prewrapMode()),
             json.dumps(self.fonts()), json.dumps(focusTo)),