pgsql: Fix function prototypes in dependency.h.

Fix function prototypes in dependency.h.

Commit 257836a7 accidentally deleted a couple of
redundant-but-conventional "extern" keywords on function prototypes.
Put them back.

Reported-by: Alvaro Herrera <alvherre@alvh.no-ip.org>

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/f315205f3fafd6f6c7c479f480289fcf45700310

Modified Files
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src/include/catalog/dependency.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)