put google analytics in quotation marks in linkedin email template

lms/templates/linkedin/linkedin_email.html

@@ -393,7 +393,7 @@
             <script type="text/javascript">
             try {
                 var _gaq = _gaq || [];
-                _gaq.push(["_setAccount", ${google_analytics}]);
+                _gaq.push(["_setAccount", "${google_analytics}"]);
                 _gaq.push(["_setDomainName", ".campaign-archive.com"]);
                 _gaq.push(["_trackPageview"]);
                 _gaq.push(["_setAllowLinker", true]);