Remove debug code accidentally added in 5051e72.

Author: Alexander Kuzmenkov

arbiter.c

@@ -355,22 +355,8 @@ static void MtmCheckResponse(MtmArbiterMessage* resp)
 	}
 }
 
-#include <execinfo.h>
-
 static void MtmScheduleHeartbeat()
 {
-	if (last_sent_heartbeat != 0 && last_sent_heartbeat + MSEC_TO_USEC(MtmHeartbeatSendTimeout)*2 < now) { 
-#define MCO_MAX_BACK_TRACE_DEPTH 256
-		int sp;
-        void* back_trace[MCO_MAX_BACK_TRACE_DEPTH];
-        int depth = backtrace(back_trace, MCO_MAX_BACK_TRACE_DEPTH);
-		char** bt = backtrace_symbols(back_trace, depth);
-		MTM_LOG1("Hearbeat interrupt: more than %lld microseconds since last heartbeat", now - last_sent_heartbeat);
-		for (sp = 0; sp < depth; sp++) {
-			MTM_LOG1("\t%s", bt[sp]);
-		}
-		free(bt);
-	}
 	if (!stop) {
 		enable_timeout_after(heartbeat_timer, MtmHeartbeatSendTimeout);
 		send_heartbeat = true;