Fix "error: ‘cout’ is not a member of ‘std’"

[un1t]

I tried to compile this code, but got error:

/xmrstak/misc/thdq.hpp:46:4: error: ‘cout’ is not a member of ‘std’ std::cout << "Error pushing an miner event" << std::endl; ^ /xmrstak/misc/thdq.hpp:46:51: error: ‘endl’ is not a member of ‘std’ std::cout << "Error pushing an miner event" << std::endl;

[bizlift]

Thanks un1t. Your fix worked for me on CentOS 7.