core: fix access to erased transaction

core/AmSipDialog.cpp

@@ -202,10 +202,10 @@ int AmSipDialog::updateStatusReply(const AmSipRequest& req, unsigned int code)
     DBG("req.method = %s; t.method = %s\n",
 	req.method.c_str(),t.method.c_str());
 
-    uas_trans.erase(t_it);
-
     if(t.method == "INVITE")
 	pending_invites--;
+
+    uas_trans.erase(t_it);
   }
 
   return 0;