fix for #124320. js error when you do "File | New Message" or hit the compose

button from addressbook, and no cards are selected. r/sr=bienvenu

mailnews/addrbook/resources/content/abCommon.js

@@ -825,6 +825,9 @@ function InitViewSortByMenu()
 
 function GenerateAddressFromCard(card)
 {
+  if (!card)
+    return "";
+
   var email;
 
   if (card.isMailList)