build: suppress CryptoPP warnings

Change-Id: I52e93fb18c42cf72d73c4477dc4a8093a5221215
diff --git a/tests/main.cpp b/tests/main.cpp
index d43aa5a..10f957c 100644
--- a/tests/main.cpp
+++ b/tests/main.cpp
@@ -6,4 +6,13 @@
 #define BOOST_TEST_MAIN 1
 #define BOOST_TEST_DYN_LINK 1
 
+#ifdef __clang__
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wunneeded-internal-declaration"
+#endif // __clang__
+
 #include <boost/test/unit_test.hpp>
+
+#ifdef __clang__
+#pragma clang diagnostic pop
+#endif // __clang__