webconfig: Don't allow exceptions from chromeos workaround

This except clause was too narrow, so it would fail here even on other
systems just because webbrowser.get() returned nothing usable

Now it will fail *later* with "could not locate runnable browser", but
at least it won't say anything about chromeos on non-chromeos systems.

share/tools/web_config/webconfig.py

@@ -113,7 +113,7 @@ def is_chromeos_garcon():
     # https://source.chromium.org/search?q=garcon-url-handler
     try:
         return "garcon-url-handler" in webbrowser.get().name
-    except AttributeError:
+    except:
         return False