pgsql: make psql honor explicit database parameter in -l mode, in case

Log Message:
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make psql honor explicit database parameter in -l mode, in case "postgres" database is missing - per complaint from Philip Yarra.

Tags:
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REL8_1_STABLE

Modified Files:
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pgsql/src/bin/psql:
startup.c (r1.126 -> r1.126.2.1)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/bin/psql/startup.c.diff?r1=1.126&r2=1.126.2.1)