Add missing ENABLE_SRTP ifdef to allow building without SRTP

FS-8571 #resolve

src/switch_rtp.c

@@ -5252,6 +5252,7 @@ static switch_status_t read_rtp_packet(switch_rtp_t *rtp_session, switch_size_t
 			if (rtp_session->has_rtcp) {
 				*flags |= SFF_RTCP;
 
+#ifdef ENABLE_SRTP
 				if (rtp_session->flags[SWITCH_RTP_FLAG_SECURE_RECV]) {
 					int sbytes = (int) *bytes;
 					err_status_t stat = 0;
@@ -5266,7 +5267,7 @@ static switch_status_t read_rtp_packet(switch_rtp_t *rtp_session, switch_size_t
 					
 					*bytes = sbytes;
 				}
-
+#endif
 				return SWITCH_STATUS_SUCCESS;
 			}
 		}