Update youtube thumbnail URL's for whats_new

Updating the youtube thumbnail urls for all items in data/whats_new. The
only thing I find odd here is that while the url is suggested on forums
like stackoverflow, it's not documented anywhere on youtube. If this url
changes we might need to integrate with youtube and pull the thumbnail
urls from the youtube api.

data/whats_new/202008210001_13_02.yml

@@ -6,7 +6,7 @@
   gitlab-com: true
   packages: [Starter, Premium, Ultimate]
   url: https://www.youtube.com/watch?v=31pNKjenlJY&feature=emb_title
-  image_url: http://i3.ytimg.com/vi/31pNKjenlJY/maxresdefault.jpg
+  image_url: https://img.youtube.com/vi/31pNKjenlJY/hqdefault.jpg
   published_at: 2020-07-22
   release: 13.2
 - title: Container Host Monitoring and Blocking
@@ -16,7 +16,7 @@
   gitlab-com: true
   packages: [All]
   url: https://www.youtube.com/watch?v=WxBzBz76FxU&feature=youtu.be
-  image_url: http://i3.ytimg.com/vi/WxBzBz76FxU/hqdefault.jpg
+  image_url: https://img.youtube.com/vi/WxBzBz76FxU/hqdefault.jpg
   published_at: 2020-07-22
   release: 13.2
 - title: Official GitLab-Figma Plugin

data/whats_new/202009150001_13_03.yml

@@ -6,7 +6,7 @@
   gitlab-com: true
   packages: [Ultimate]
   url: https://www.youtube.com/watch?v=3wdWMDRLdp4
-  image_url: http://i3.ytimg.com/vi/3wdWMDRLdp4/hqdefault.jpg
+  image_url: https://img.youtube.com/vi/3wdWMDRLdp4/hqdefault.jpg
   published_at: 2020-08-22
   release: 13.3
 - title: Create a matrix of jobs using a simple syntax

data/whats_new/202009300001_13_04.yml

@@ -46,7 +46,7 @@
   gitlab-com: true
   packages: [starter, premium, ultimate]
   url: https://www.youtube.com/embed/1FBRaBQTQZk
-  image_url: http://i3.ytimg.com/vi/1FBRaBQTQZk/maxresdefault.jpg
+  image_url: https://img.youtube.com/vi/1FBRaBQTQZk/hqdefault.jpg
   published_at: 2020-09-22
   release: 13.4
 - title: Quick navigation using the Search bar