Don't add insecure trackers on a https site

webtorrent/webtorrent#67 (comment)

Author: DiegoRBaquero

client.js

@@ -86,7 +86,15 @@ function Client (peerId, port, torrent, opts) {
         return new HTTPTracker(self, announceUrl)
       } else if (protocol === 'udp:' && typeof UDPTracker === 'function') {
         return new UDPTracker(self, announceUrl)
-      } else if ((protocol === 'ws:' || protocol === 'wss:') && webrtcSupport) {
+      } else if (((protocol === 'ws:') || protocol === 'wss:') && webrtcSupport) {
+        // Don't try to add http tracker on an https website
+        if (protocol === 'ws:' && location && location.protocol && location.protocol === 'https:') {
+          process.nextTick(function () {
+            var err = new Error('unsupported http tracker on https: ' + announceUrl)
+            self.emit('warning', err)
+          })
+          return null
+        }
         return new WebSocketTracker(self, announceUrl)
       } else {
         process.nextTick(function () {