Make enter in bookmarks manager reuse existing windows like double-click

does.  Bug 121085, r=doron, sr=blake

xpfe/components/bookmarks/resources/bookmarks.xml

@@ -1643,7 +1643,7 @@
       <vbox flex="1">
         <outliner anonid="bookmarks-outliner" flex="1" class="plain" enableColumnDrag="true"
                   datasources="rdf:bookmarks rdf:internetsearch rdf:files rdf:localsearch" ref="NC:BookmarksRoot" flags="dont-build-content"
-                  onkeypress="if (event.keyCode == 13) this.parentNode.parentNode.openItem(event, true);"
+                  onkeypress="if (event.keyCode == 13) this.parentNode.parentNode.openItem(event, false);"
                   ondblclick="if (event.originalTarget.localName == 'outlinerchildren') this.parentNode.parentNode.openItem(event, false);"
                   ondraggesture="if (event.originalTarget.localName == 'outlinerchildren') nsDragAndDrop.startDrag(event, this.parentNode.parentNode.DNDObserver);"
                   onselect="this.parentNode.parentNode.view.selectionChanged();">