obs-nvenc: Support new error code for too many sessions

At some point NVIDIA started using NV_ENC_ERR_INCOMPATIBLE_CLIENT_KEY
instead of NV_ENC_ERR_OUT_OF_MEMORY to signal that the session limit
has been exceeded.

plugins/obs-nvenc/nvenc-helpers.c

@@ -64,6 +64,7 @@ bool nv_failed2(obs_encoder_t *encoder, void *session, NVENCSTATUS err,
 
 	switch (err) {
 	case NV_ENC_ERR_OUT_OF_MEMORY:
+	case NV_ENC_ERR_INCOMPATIBLE_CLIENT_KEY:
 		obs_encoder_set_last_error(encoder,
 					   obs_module_text("TooManySessions"));
 		break;