Limit tampering with standard C++ library to Linux
Limit tampering with standard C++ library to Linux

Otherwise it breaks e.g. FreeBSD build where it is not needed at all

brain5lug/i2pd,brain5lug/i2pd,PurpleI2P/i2pd,PurpleI2P/i2pd,majestrate/i2pd,PurpleI2P/i2pd,PurpleI2P/i2pd,majestrate/i2pd,brain5lug/i2pd,majestrate/i2pd,majestrate/i2pd,brain5lug/i2pd,majestrate/i2pd