Remove assert from dtm_sleep

Author: knizhnik

src/backend/access/transam/global_snapshot.c

@@ -171,7 +171,6 @@ dtm_sleep(timestamp_t interval)
 		if (dtm_get_current_time() < waketm)
 		{
 			totalSleepInterrupts += 1;
-			Assert(errno == EINTR);
 			continue;
 		}
 		break;