Replace std::random_shuffle with std::shuffle

According to [1], std::random_shuffle is deprecated in C++14 and removed
in C++17. Since std::shuffle is available since C++11 as a replacement
and monero already requires C++11, this is a good replacement.

[1]: https://en.cppreference.com/w/cpp/algorithm/random_shuffle

src/p2p/net_peerlist.h

@@ -290,7 +290,7 @@ namespace nodetool
 
     if (anonymize)
     {
-      std::random_shuffle(bs_head.begin(), bs_head.end());
+      std::shuffle(bs_head.begin(), bs_head.end(), std::default_random_engine(crypto::rand<unsigned>()));
       if (bs_head.size() > depth)
         bs_head.resize(depth);
       for (auto &e: bs_head)

tests/unit_tests/ringct.cpp

@@ -779,8 +779,8 @@ TEST(ringct, range_proofs_accept_very_long_simple)
     inputs[n] = n;
     outputs[n] = n;
   }
-  std::random_shuffle(inputs, inputs + N);
-  std::random_shuffle(outputs, outputs + N);
+  std::shuffle(inputs, inputs + N, std::default_random_engine(crypto::rand<unsigned>()));
+  std::shuffle(outputs, outputs + N, std::default_random_engine(crypto::rand<unsigned>()));
   EXPECT_TRUE(range_proof_test(true, NELTS(inputs), inputs, NELTS(outputs), outputs, false, true));
 }