soup: work around frequent deadlocks in GLib type initialisation

.. by registering the types from the plugin init function. This
seems to help, but we'll see if it's enough (might need similar
things elsewhere).

https://bugzilla.gnome.org/show_bug.cgi?id=693911
https://bugzilla.gnome.org/show_bug.cgi?id=674885

ext/soup/gstsoup.c

@@ -34,6 +34,20 @@ plugin_init (GstPlugin * plugin)
   bind_textdomain_codeset (GETTEXT_PACKAGE, "UTF-8");
 #endif
 
+  /* see https://bugzilla.gnome.org/show_bug.cgi?id=674885 */
+  g_type_ensure (G_TYPE_SOCKET);
+  g_type_ensure (G_TYPE_SOCKET_ADDRESS);
+  g_type_ensure (G_TYPE_SOCKET_SERVICE);
+  g_type_ensure (G_TYPE_SOCKET_FAMILY);
+  g_type_ensure (G_TYPE_SOCKET_CLIENT);
+  g_type_ensure (G_TYPE_RESOLVER);
+  g_type_ensure (G_TYPE_PROXY_RESOLVER);
+  g_type_ensure (G_TYPE_PROXY_ADDRESS);
+  g_type_ensure (G_TYPE_TLS_CERTIFICATE);
+  g_type_ensure (G_TYPE_TLS_CONNECTION);
+  g_type_ensure (G_TYPE_TLS_DATABASE);
+  g_type_ensure (G_TYPE_TLS_INTERACTION);
+
   gst_element_register (plugin, "souphttpsrc", GST_RANK_PRIMARY,
       GST_TYPE_SOUP_HTTP_SRC);
   gst_element_register (plugin, "souphttpclientsink", GST_RANK_NONE,