Update libsrtp to 1.5.2

libsrtp.gyp

Index: libsrtp.gyp
diff --git a/libsrtp.gyp b/libsrtp.gyp
index 0b96d413459b834e22f60b77875e9f63d7ec72ae..27e647616894f45afcb5efb0ee0b69ad013817f0 100644
--- a/libsrtp.gyp
+++ b/libsrtp.gyp
@@ -200,7 +200,6 @@
                 'srtp/crypto/hash/sha1.c',
                 'srtp/crypto/rng/ctr_prng.c',
                 'srtp/crypto/rng/prng.c',
-                'srtp/crypto/rng/rand_source.c',
               ],
               'sources': [
                 'srtp/crypto/cipher/aes_gcm_ossl.c',
@@ -208,7 +207,6 @@
                 'srtp/crypto/hash/hmac_ossl.c',
                 'srtp/crypto/include/aes_gcm_ossl.h',
                 'srtp/crypto/include/aes_icm_ossl.h',
-                'srtp/crypto/rng/rand_source_ossl.c',
               ],
             }],
           ],
@@ -293,6 +291,8 @@
           ],
           'sources': [
             'srtp/crypto/test/cipher_driver.c',
+            'srtp/include/getopt_s.h',
+            'srtp/test/getopt_s.c',
           ],
           'conditions': [
             ['use_openssl==1', {
@@ -340,6 +340,8 @@
           ],
           'sources': [
             'srtp/crypto/test/kernel_driver.c',
+            'srtp/include/getopt_s.h',
+            'srtp/test/getopt_s.c',
           ],
         },
         {
@@ -360,6 +362,8 @@
           ],
           'sources': [
             'srtp/crypto/test/rand_gen.c',
+            'srtp/include/getopt_s.h',
+            'srtp/test/getopt_s.c',
           ],
         },
         {
@@ -370,6 +374,8 @@
           ],
           'sources': [
             'srtp/crypto/test/rand_gen_soak.c',
+            'srtp/include/getopt_s.h',
+            'srtp/test/getopt_s.c',
           ],
         },
         {