don't require collection for top toolbar

This is a hack, and ideally the code would be refactored
so that the entire main window is not loaded until a collection
is available, but doing that will break a bunch of add-ons.

Fixes
https://anki.tenderapp.com/discussions/beta-testing/1276-anki-215-beta#comment_46241878

aqt/toolbar.py

@@ -18,6 +18,7 @@ class Toolbar:
             "sync": self._syncLinkHandler,
         }
         self.web.setFixedHeight(30)
+        self.web.requiresCol = False
 
     def draw(self):
         self.web.onBridgeCmd = self._linkHandler

aqt/webview.py

@@ -91,6 +91,7 @@ class AnkiWebView(QWebEngineView):
 
         self._domDone = True
         self._pendingActions = []
+        self.requiresCol = True
         self.setPage(self._page)
 
         self._page.profile().setHttpCacheType(QWebEngineProfile.NoCache)
@@ -319,7 +320,11 @@ body {{ zoom: {}; {} }}
         # async web events may be received after the profile has been closed
         # or the underlying webview has been deleted
         from aqt import mw
-        return not mw.col or sip.isdeleted(self)
+        if sip.isdeleted(self):
+            return True
+        if not mw.col and self.requiresCol:
+            return True
+        return False
 
     def _onBridgeCmd(self, cmd):
         if self._shouldIgnoreWebEvent():