fixed https request issue

app/client/head.html

@@ -27,7 +27,7 @@
     <meta name="theme-color" content="#ffffff">
     <link href='https://fonts.googleapis.com/css?family=Roboto' rel='stylesheet' type='text/css'>
     <link href="https://fonts.googleapis.com/icon?family=Material+Icons" rel="stylesheet">
-    <link href='http://fonts.googleapis.com/css?family=Oxygen:400,300,700' rel='stylesheet' type='text/css'>
+    <link href='https://fonts.googleapis.com/css?family=Oxygen:400,300,700' rel='stylesheet' type='text/css'>
     <script src="/jquery.textcomplete.min.js"></script>
     <script src="/emojidropdown.js"></script>
     <script type="application/javascript">