make sure css is always available in deck browser

aqt/deckbrowser.py

@@ -148,9 +148,9 @@ a { font-size: 80%; }
 """
 
     def _renderPage(self):
+        css = self.mw.sharedCSS + self._css
         if self._decks:
             buf = ""
-            css = self.mw.sharedCSS + self._css
             max=len(self._decks)-1
             buf += "<tr><th></th><th align=right>%s</th>" % _("Due")
             buf += "<th align=right>%s</th><th></th></tr>" % _("New")

aqt/plugins.py

@@ -2,7 +2,7 @@
 # -*- coding: utf-8 -*-
 # License: GNU GPL, version 3 or later; http://www.gnu.org/copyleft/gpl.html
 
-import sys, os, re
+import sys, os, re, traceback
 from PyQt4.QtCore import *
 from PyQt4.QtGui import *
 from aqt.utils import showInfo, showWarning, openFolder