fix for bug #51546. work around for the bug that the onselect handler

gets called twice.  this was causing the frame src to be set twice
which was interrupting the file loading from the JAR.  r=alecf,putterman

mailnews/base/prefs/resources/content/AccountManager.js

@@ -358,13 +358,29 @@ function setEnabled(control, enabled)
     control.setAttribute("disabled", true);
 }
 
+// this is a workaround for bug #51546
+// the on click handler is getting called twice
+var bug51546CurrentPage = null;
+var bug51546CurrentServerId = null;
+
 //
 // called when someone clicks on an account
 // figure out context by what they clicked on
 //
 function onAccountClick(tree) {
+  //dump("onAccountClick()\n");
+
   var result = getServerIdAndPageIdFromTree(tree);
 
+  //dump("sputter:"+bug51546CurrentPage+","+bug51546CurrentServerId+":"+result.pageId+","+result.serverId+"\n");
+  if ((bug51546CurrentPage == result.pageId) && (bug51546CurrentServerId == result.serverId)) {
+	//dump("workaround for #51546\n");
+	return;
+  }
+  
+  bug51546CurrentPage = result.pageId;
+  bug51546CurrentServerId = result.serverId;
+  
   if (result) {
 	  showPage(result.serverId, result.pageId);
 	  updateButtons(tree,result.serverId);