fix and enable bip32 unit test

the bip32 unit test was not included in the make process

src/test/bip32_tests.cpp

@@ -8,6 +8,7 @@
 #include "key.h"
 #include "uint256.h"
 #include "util.h"
+#include "utilstrencodings.h"
 #include "test/test_bitcoin.h"
 
 #include <string>