fix for 78060;adding insertsmiley menu item in mailcompose insert menu; r=ducarroz;sr=bienvenu;

editor/ui/composer/content/editorOverlay.xul

@@ -397,7 +397,7 @@
       <menuitem accesskey="&inserthline.accesskey;"      observes="cmd_hline"       label="&insertHLineCmd.label;"/>
       <menuitem accesskey="&HTMLSourceMode.accesskey;"   observes="cmd_insertHTML"  key="inserthtmlkb"/>
       <menuitem accesskey="&insertchars.accesskey;"      observes="cmd_insertChars" />
-      <menuseparator/>
+      <menuseparator id="insertMenuSeparator"/>
 <!-- Activate this after Enter key inserts P tag and not BR
       <menuitem accesskey="&insertbreak.accesskey;"      observes="cmd_insertBreak"      label="&insertBreakCmd.label;"/>
 -->