rabbitmq: remove deprecation warning

From https://github.com/alanxz/rabbitmq-c/blob/c3e4176659aac7d0e497da90a46c08c63b98282a/include/rabbitmq-c/ssl_socket.h#L250
> * \deprecated Since v0.13.0 this is a no-op. OpenSSL automatically manages
> *    library initialization and uninitialization.

> Warning: rabbitmq.c:574:3: warning: 'amqp_set_initialize_ssl_library' is deprecated [-Wdeprecated-declarations]
>                 amqp_set_initialize_ssl_library(1);
>                 ^
> /usr/include/rabbitmq-c/ssl_socket.h:249:1: note: 'amqp_set_initialize_ssl_library' has been explicitly marked deprecated here
> AMQP_DEPRECATED_EXPORT
> ^
> /usr/include/rabbitmq-c/export.h:29:46: note: expanded from macro 'AMQP_DEPRECATED_EXPORT'
> #  define AMQP_DEPRECATED_EXPORT AMQP_EXPORT AMQP_DEPRECATED
>                                              ^
> /usr/include/rabbitmq-c/export.h:25:43: note: expanded from macro 'AMQP_DEPRECATED'
> #  define AMQP_DEPRECATED __attribute__ ((__deprecated__))
>                                           ^
> 1 warning generated.

(cherry picked from commit a2f7147dded679d025a902aa12beb048ee714c32)

src/modules/rabbitmq/rabbitmq.c

@@ -87,7 +87,9 @@ static int max_reconnect_attempts = 1;
 static int timeout_sec = 1;
 static int timeout_usec = 0;
 static int direct_reply_to = 0;
+#if AMQP_VERSION_MAJOR == 0 && AMQP_VERSION_MINOR < 13
 static int amqp_ssl_init_called = 0;
+#endif
 
 /* module helper functions */
 static int rabbitmq_connect(amqp_connection_state_t *conn);
@@ -570,12 +572,14 @@ static int rabbitmq_connect(amqp_connection_state_t *conn)
 	int log_ret;
 	//	amqp_rpc_reply_t reply;
 
+#if AMQP_VERSION_MAJOR == 0 && AMQP_VERSION_MINOR < 13
 	// amqp_ssl_init_called should only be called once
 	if(amqp_info.ssl && !amqp_ssl_init_called) {
 		amqp_set_initialize_ssl_library(1);
 		amqp_ssl_init_called = 1;
 		LM_DBG("AMQP SSL library initialized\n");
 	}
+#endif
 
 	// establish a new connection to RabbitMQ server
 	*conn = amqp_new_connection();