Avoid mixed content warning through oEmbed content

- Switch dailymotion oEmbed endpoint to https
- Accept Mixcloud https URLs
- Accept dailymotion https URLs

config/oembed_providers.yml

@@ -3,9 +3,10 @@
 # note that 'endpoint' is the only information
 # in OEmbed that we can trust. anything else may be spoofed!
 daily_motion:
-  endpoint: "http://www.dailymotion.com/services/oembed"
+  endpoint: "https://www.dailymotion.com/services/oembed"
   urls:
     - http://www.dailymotion.com/video/*
+    - https://www.dailymotion.com/video/*
 
 twitter:
   endpoint: "https://api.twitter.com/1/statuses/oembed.json"
@@ -16,4 +17,5 @@ twitter:
 mixcloud:
   endpoint: "http://www.mixcloud.com/oembed/"
   urls:
-    - http://www.mixcloud.com/*/*
+    - http://www.mixcloud.com/*/*
+    - https://www.mixcloud.com/*/*