Comment out http_proxy in example config (#5151)

The http_proxy section was not commented out in the example config
causing Invidious to error out unless an HTTP proxy was configured.

This problem affects new manual installs in which the example config
is copied to create the actual config Invidious uses

config/config.example.yml

@@ -178,11 +178,11 @@ https_only: false
 ##
 ## If unset, then no HTTP proxy will be used.
 ## 
-http_proxy:
-  user:
-  password:
-  host:
-  port:
+#http_proxy:
+#  user:
+#  password:
+#  host:
+#  port:
 
 
 ##