statistics: only load the Flot library when we need it

kallithea/templates/base/root.html

@@ -70,7 +70,6 b''
         <script type="text/javascript" src="${h.url('/js/jquery.dataTables.min.js', ver=c.kallithea_version)}"></script>
         <script type="text/javascript" src="${h.url('/js/bootstrap.js', ver=c.kallithea_version)}"></script>
         <script type="text/javascript" src="${h.url('/js/select2/select2.js', ver=c.kallithea_version)}"></script>
-        <script type="text/javascript" src="${h.url('/js/yui.flot.js', ver=c.kallithea_version)}"></script>
         <script type="text/javascript" src="${h.url('/js/native.history.js', ver=c.kallithea_version)}"></script>
         <script type="text/javascript" src="${h.url('/js/base.js', ver=c.kallithea_version)}"></script>
         ## EXTRA FOR JS

kallithea/templates/summary/statistics.html

@@ -15,6 +15,7 b''
 <%block name="head_extra">
   <link href="${h.url('atom_feed_home',repo_name=c.db_repo.repo_name,api_key=request.authuser.api_key)}" rel="alternate" title="${_('%s ATOM feed') % c.repo_name}" type="application/atom+xml" />
   <link href="${h.url('rss_feed_home',repo_name=c.db_repo.repo_name,api_key=request.authuser.api_key)}" rel="alternate" title="${_('%s RSS feed') % c.repo_name}" type="application/rss+xml" />
+  <script type="text/javascript" src="${h.url('/js/yui.flot.js', ver=c.kallithea_version)}"></script>
 </%block>
 
 <%def name="main()">