added an info about data persistence for the spam reports

_locales/en/messages.json

@@ -1363,6 +1363,10 @@
     "message": "Spam Filter Reports",
     "description": ""
   },
+  "SpamReport_infoline": {
+    "message": "This information is saved only for the current session.",
+    "description": ""
+  },
   "Date": {
     "message": "Date",
     "description": ""

pages/spamfilter/mzta-spamfilter.html

@@ -57,7 +57,8 @@
     <button type="button" id="accounts_deselect_all">__MSG_DeselectAll__</button>
     </div>
     <div id="spamfitler_reports_container">
-      <h2>__MSG_SpamReport_Title__</h2>
+      <div><span  class="section_title">__MSG_SpamReport_Title__</span>
+      <br><span class="infoline">__MSG_SpamReport_infoline__</span></div>
       <table id="report_data">
           <thead>
               <tr>