Bug 121634 JS error: viewer.onpopupshowingContext is not a function

r=caillon sr=bz

extensions/inspector/resources/content/viewers/jsObject/jsObject.xul

@@ -24,7 +24,7 @@
   </commandset>
   
   <popupset>
-    <popup id="popupContext" onpopupshowing="return viewer.onpopupshowingContext(this)">
+    <popup id="popupContext">
       <menuitem label="&inspectNewWindow.label;" observes="cmdInspectInNewView"/>
       <menuseparator/>
       <menuitem label="&jsCopyValue.label;" observes="cmdCopyValue"/>