ErrorController: Send status code even when not rendering.

Previously, if the current extension were not in allowed_render_styles,
the error's HTTP status code would be swallowed and turned into a 200.
This meant that 404ing stylesheets were actually sending back the text
"404" as an "OK" stylesheet.

r2/r2/controllers/error.py

@@ -165,6 +165,7 @@ class ErrorController(RedditController):
             if c.render_style not in self.allowed_render_styles:
                 if code not in (204, 304):
                      c.response.content = str(code)
+                c.response.status_code = code
                 return c.response
             elif c.render_style == "api":
                 data = request.environ.get('extra_error_data', {'error': code})