Fix Coverity Scan Warning(CID 185437).

Coverity Scan Report: 
    >>> CID 185437:  Incorrect expression  (ASSERT_SIDE_EFFECT)
    >>> Argument "connected" of Assert() has a side effect because the variable is volatile.  
            The containing function might work differently in a non-debug build.

To fix this, we can simply remove this Assert because if the process reached here, it must not have thrown
any exceptions.

src/backend/utils/gdd/gddbackend.c

@@ -571,7 +571,6 @@ buildWaitGraph(GddCtx *ctx)
 	}
 	PG_END_TRY();
 
-	Assert(connected);
 	SPI_finish();
 	/* Make sure we are in gddContext */
 	MemoryContextSwitchTo(gddContext);