CMakeLists.txt: check CMAKE_SYSTEM_PROCESSOR

Check CMAKE_SYSTEM_PROCESSOR when generating NSIS package.
This allows us correctly determine install dir on Windows

CMakeLists.txt

@@ -649,7 +649,11 @@ if(WIN32)
 	else()
 		set(CPACK_NSIS_PACKAGE_NAME "VCMI ${CPACK_PACKAGE_VERSION} ${PACKAGE_NAME_SUFFIX} ")
 	endif()
-	set(CPACK_NSIS_INSTALL_ROOT "$PROGRAMFILES")
+	if(CMAKE_SYSTEM_PROCESSOR MATCHES ".*64")
+		set(CPACK_NSIS_INSTALL_ROOT "$PROGRAMFILES64")
+	else()
+		set(CPACK_NSIS_INSTALL_ROOT "$PROGRAMFILES")
+	endif()
 	if(ENABLE_LAUNCHER)
 		set(CPACK_PACKAGE_EXECUTABLES "VCMI_launcher;VCMI")
 		set(CPACK_NSIS_EXTRA_INSTALL_COMMANDS " CreateShortCut \\\"$DESKTOP\\\\VCMI.lnk\\\" \\\"$INSTDIR\\\\VCMI_launcher.exe\\\"")