Make sure we honour config_api.load_autoconfig even with errors

We don't raise ConfigFileErrors inside read_config_py so we can get back the
config_api object. Instead we raise it in config.init().

qutebrowser/config/config.py

@@ -660,15 +660,19 @@ def init(parent=None):
     objreg.register('config-commands', config_commands)
 
     global _errbox
+    config_api = None
+
     try:
         config_api = configfiles.read_config_py()
+        # Raised here so we get the config_api back.
+        if config_api.errors:
+            raise configexc.ConfigFileErrors('config.py', config_api.errors)
     except configexc.ConfigFileErrors as e:
         _errbox = msgbox.msgbox(parent=None,
                                 title="Error while reading config",
                                 text=e.to_html(),
                                 icon=QMessageBox.Warning,
                                 plain_text=False)
-        config_api = None
     else:
         _errbox = None
 

qutebrowser/config/configfiles.py

@@ -193,9 +193,6 @@ def read_config_py(filename=None):
             exception=e, traceback=traceback.format_exc()))
 
     api.finalize()
-    if api.errors:
-        raise configexc.ConfigFileErrors(basename, api.errors)
-
     return api