MinGW: Fix compiler warning about winsock2.h and windows.h

This commit fixes following compiler warning with mingw compiler:

In file included from common.h:63:0,
                 from util_security.h:42,
                 from util_security.cc:36:
/usr/share/mingw-w64/include/winsock2.h:15:2: warning: #warning
 Please include winsock2.h before windows.h [-Wcpp]
 #warning Please include winsock2.h before windows.h
Fix typo
MinGW: Fix compiler warning with -Wstrict-aliasing

The error message is:

warning: dereferencing type-punned pointer will break strict-aliasing
rules [-Wstrict-aliasing]