Blender Git Loki

Fix T93184: Link color not used for custom sockets

D13044 allowed the link color overlay to be used with custom sockets.
This no longer works due to a condition that checks if the socket is
standard or not, which was in place to avoid bad indexing of the
std_node_socket_colors array. Since that array is no longer used, this
condition needs to be removed.

Differential Revision: https://developer.blender.org/D13274

Reviewed By: Hans Goudey