pjproject_bundled: Disable srtp use by pjmedia

The reason for the disable is that while Asterisk works fine with older
libsrtp versions, newer versions of pjproject won't compile with them.
Debian 6 for instance, has libsrtp 1.4.4 which is older than what
pjproject is expecting.

We don't use most of pjmedia but we DO use it for SDP negotiation.
Luckily disabling srtp in pjmedia doesn't interfere with it's ability
to negitiate a secure channel.  The proper crypto attributes are
negotiated in both directions.

ASTERISK-26279 #close

Change-Id: Id25a92cdf3df97a26c53cffae65b6b82de33c8e2

third-party/pjproject/patches/config_site.h

@@ -4,6 +4,14 @@
 
 #include <sys/select.h>
 
+/*
+ * Defining PJMEDIA_HAS_SRTP to 0 does NOT disable Asterisk's ability to use srtp.
+ * It only disables the pjmedia srtp transport which Asterisk doesn't use.
+ * The reason for the disable is that while Asterisk works fine with older libsrtp
+ * versions, newer versions of pjproject won't compile with them.
+ */
+#define PJMEDIA_HAS_SRTP 0
+
 #define PJ_HAS_IPV6 1
 #define NDEBUG 1
 #define PJ_MAX_HOSTNAME (256)