pgsql: Modify copyright.pl so all lines are processed, not just the fir

Modify copyright.pl so all lines are processed, not just the first
match, so files that contain embedded copyrights are updated, e.g.
pgsql/help.c.

Backpatch to 9.2.

Branch
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REL9_2_STABLE

Details
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http://git.postgresql.org/pg/commitdiff/efd07bd1364267c7e223d9e8bdcad1a201809ed8

Modified Files
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src/tools/copyright.pl | 10 ++++------
1 files changed, 4 insertions(+), 6 deletions(-)