Update libsrtp to upstream 1.5.0

srtp/crypto/math/datatypes.c

Index: srtp/crypto/math/datatypes.c
diff --git a/srtp/crypto/math/datatypes.c b/srtp/crypto/math/datatypes.c
index 609a057d6a8ba03fc141ea8e6e0078625b608bcb..5352fcd491be87968eef8f54292bca1d6198a2d2 100644
--- a/srtp/crypto/math/datatypes.c
+++ b/srtp/crypto/math/datatypes.c
@@ -43,6 +43,10 @@
  *
  */
 
+#ifdef HAVE_CONFIG_H
+    #include <config.h>
+#endif
+
 #include "datatypes.h"
 
 int 
@@ -688,6 +692,7 @@ base64_char_to_sextet(uint8_t c) {
  return -1;
 }
 
+#ifdef INCLUDE_DEAD_CODE
 /*
  * base64_string_to_octet_string converts a hexadecimal string
  * of length 2 * len to a raw octet string of length len
@@ -716,3 +721,4 @@ base64_string_to_octet_string(char *raw, char *base64, int len) {
   }
   return base64_len;
 }
+#endif