cmake: only use _FORTIFY_SOURCE with hardening

Author: illwieckz

cmake/DaemonFlags.cmake

@@ -315,7 +315,7 @@ else()
 	endif()
 
 	# Hardening.
-	if (USE_HARDENING OR NOT MINGW)
+	if (USE_HARDENING)
 		# MinGW with _FORTIFY_SOURCE and without -fstack-protector
 		# causes unsatisfied dependency on libssp.
 		# https://github.com/msys2/MINGW-packages/issues/5868