add missing file

mail/extensions/offline/locale/contents.rdf.in

@@ -0,0 +1,23 @@
+<?xml version="1.0"?>
+<RDF:RDF xmlns:RDF="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
+         xmlns:chrome="http://www.mozilla.org/rdf/chrome#">
+
+  <!-- list all the skins being supplied by this package -->
+  <RDF:Seq about="urn:mozilla:locale:root">
+    <RDF:li resource="urn:mozilla:locale:en-US"/>
+  </RDF:Seq>
+
+  <!-- locale information -->
+  <RDF:Description about="urn:mozilla:locale:en-US">
+    <chrome:packages>
+      <RDF:Seq about="urn:mozilla:locale:en-US:packages">
+        <RDF:li resource="urn:mozilla:locale:en-US:messenger-offline"/>
+      </RDF:Seq>
+    </chrome:packages>
+  </RDF:Description>
+
+  <!-- Version Information.  State that we work only with major version of this
+       package. -->
+  <RDF:Description about="urn:mozilla:locale:en-US:messenger-offline"
+	chrome:localeVersion="@MOZILLA_VERSION@"/>
+</RDF:RDF>