Eliminate debug pref: show about box as modal.

b=86780; r=morse; sr=alecf

suite/common/pref/pref-debug.xul

@@ -75,8 +75,6 @@
               prefstring="nglayout.debug.enable_xbl_forms"/>
     <checkbox id="nglayoutDebugEnableXPCOMRefcntLog" label="&debugEnableXPCOMRefcntLog.label;"
               prefstring="nglayout.debug.enable_xpcom_refcnt_log"/>
-    <checkbox id="showAboutAsStupidModalWindow" label="&debugShowAboutAsModal.label;"
-              prefstring="browser.show_about_as_stupid_modal_window"/>
   </groupbox>              
 
 

suite/locales/en-US/chrome/common/pref/pref-debug.dtd

@@ -11,7 +11,6 @@
 <!ENTITY debugStrictJavascript.label     "Show strict JavaScript warnings">
 <!ENTITY debugUseXBLForms.label          "Use XBL-based form controls (takes effect after restart). These are still under construction.">
 <!ENTITY debugEnableXPCOMRefcntLog.label "Enable XPCOM Refcount Log">
-<!ENTITY debugShowAboutAsModal.label     "Show 'About' as modal dialog">
 
 <!-- Debug: Turn on gfx-rendered widgets -->
 <!ENTITY widgetRendering.label "Rendering">