pgsql: Fix numericlocale psql option when used with a null string and

Log Message:
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Fix numericlocale psql option when used with a null string and latex and troff
formats; a null string must not be formatted as a numeric. The more exotic
formats latex and troff also incorrectly formatted all strings as numerics
when numericlocale was on.

Backpatch to 8.1 where numericlocale option was added.

This fixes bug #5355 reported by Andy Lester.

Tags:
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REL8_3_STABLE

Modified Files:
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    pgsql/src/bin/psql:
        print.c (r1.96 -> r1.96.2.1)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/bin/psql/print.c?r1=1.96&r2=1.96.2.1)