Fix build error in MinGW

and fix a misuse of CopyFileEx function.

PowerEditor/gcc/include/various.h

@@ -11,7 +11,7 @@
 //TBSTYLE_EX_HIDECLIPPEDBUTTONS = 501
 //#define _WIN32_IE 0x501
 //Theme (uxtheme)
-#define _WIN32_WINNT 0x0501
+#define _WIN32_WINNT 0x0600
 
 //#include <windows.h>
 

PowerEditor/src/NppIO.cpp

@@ -1566,8 +1566,8 @@ bool Notepad_plus::fileSave(BufferID id)
 				}
 			}
 
-			BOOL keepGoing = TRUE;
+			BOOL doCancel = FALSE;
-			if (!::CopyFileEx(fn, fn_bak.c_str(), nullptr, nullptr, &keepGoing, COPY_FILE_NO_BUFFERING))
+			if (!::CopyFileEx(fn, fn_bak.c_str(), nullptr, nullptr, &doCancel, COPY_FILE_NO_BUFFERING))
 			{
 				int res = _nativeLangSpeaker.messageBox("FileBackupFailed",
 					_pPublicInterface->getHSelf(),