build issue when openssl is not available

panda/src/express/hashVal.cxx

@@ -14,10 +14,12 @@
 
 #include "hashVal.h"
 #include "virtualFileSystem.h"
-#include "openSSLWrapper.h"  // must be included before any other openssl.
-#include "openssl/md5.h"
 #include <ctype.h>
 
+#ifdef HAVE_OPENSSL
+#include "openSSLWrapper.h"  // must be included before any other openssl.
+#include "openssl/md5.h"
+#endif  // HAVE_OPENSSL
 
 
 ////////////////////////////////////////////////////////////////////