fixup! Bug 41600: Add a tor circuit display panel.

Bug 41770 - Stop blocking event propagation of keydown events that we do
not handle. This lets the arrow key events pass on to
ToolbarKeyboardNavigator.

browser/components/torcircuit/content/torCircuitPanel.js

@@ -220,10 +220,10 @@ var gTorCircuitPanel = {
     // rather than a <html:button>, or <xul:toolbarbutton>, so we need to set up
     // listeners for both "click" and "keydown", and not for "command".
     this.toolbarButton.addEventListener("keydown", event => {
-      event.stopPropagation();
       if (event.key !== "Enter" && event.key !== " ") {
         return;
       }
+      event.stopPropagation();
       this.show();
     });
     this.toolbarButton.addEventListener("click", event => {