Incorrect render target index assignment in GLSLBackend

else if (Semantic && FCStringAnsi::Strnicmp(Variable->name, "gl_", 3) != 0)
{
	Variable->explicit_location = 1;
	Variable->semantic = ralloc_strdup(Variable, Semantic);
	if(Mode == ir_var_in)
	{
		Variable->location = ParseState->next_in_location_slot++;
	}
	else
	{
		Variable->location = ParseState->next_out_location_slot++;
	}
}