[poco] Not automatically copy pcre.dll in debug mode

[sdcb]

(Releated to: #124)

Consider the following code:

#include <Poco\RegularExpression.h>
#include <iostream>

int main()
{
	std::cout << Poco::RegularExpression::match("\\d+", "12");
}

Run this code will report the following message:
The program can’t start because pcre.dll is missing from your computer.
Release build is good.

I checked the poco built process, found that poco debug built linked to the release pcre lib, I think that caused the problem.