freeswitch-stable: fix implicit declaration error

Since the update to openssl-1.1.1a the compile fails like this:

  CC       src/libfreeswitch_la-switch_rtp.lo
src/switch_rtp.c: In function 'switch_rtp_get_random':
src/switch_rtp.c:2419:2: error: implicit declaration of function 'RAND_bytes'; did you mean 'RSA_bits'? [-Werror=implicit-function-declaration]
  RAND_bytes(buf, len);
  ^~~~~~~~~~
  RSA_bits
cc1: all warnings being treated as errors
make[4]: *** [Makefile:2377: src/libfreeswitch_la-switch_rtp.lo] Error 1

This patch adds the missing include.

Signed-off-by: Sebastian Kemper <sebastian_ml@gmx.net>

net/freeswitch-stable/patches/390-switch-rtp_c-fix-implicit-declaration-of-function-RAND_bytes.patch

@@ -0,0 +1,10 @@
+--- a/src/include/switch_ssl.h
++++ b/src/include/switch_ssl.h
+@@ -38,6 +38,7 @@
+ #endif
+ #include <openssl/crypto.h>
+ #include <openssl/pem.h>
++#include <openssl/rand.h>
+ #include <openssl/conf.h>
+ #include <openssl/x509v3.h>
+ #ifndef OPENSSL_NO_ENGINE