Update abstime expected results to match post-30-June-2001 reality.

Probably the right fix is to remove 'current' special value entirely,
but I don't want to see regression test failures until that happens.

src/test/regress/expected/abstime-solaris-1947.out

@@ -47,10 +47,9 @@ SELECT '' AS six, ABSTIME_TBL.*
      | Sun Jan 14 03:14:21 1973 PST
      | Mon May 01 00:30:30 1995 PDT
      | epoch
-     | current
      | -infinity
      | Sat May 10 23:59:12 1947 PDT
-(6 rows)
+(5 rows)
 
 SELECT '' AS six, ABSTIME_TBL.*
    WHERE ABSTIME_TBL.f1 > abstime '-infinity';

src/test/regress/expected/abstime.out

@@ -47,10 +47,9 @@ SELECT '' AS six, ABSTIME_TBL.*
      | Sun Jan 14 03:14:21 1973 PST
      | Mon May 01 00:30:30 1995 PDT
      | epoch
-     | current
      | -infinity
      | Sat May 10 23:59:12 1947 PST
-(6 rows)
+(5 rows)
 
 SELECT '' AS six, ABSTIME_TBL.*
    WHERE ABSTIME_TBL.f1 > abstime '-infinity';