pgsql: Properly pass -c parameter to ecpg when building regression

Log Message:
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Properly pass -c parameter to ecpg when building regression tests.
Per Michael.

Modified Files:
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pgsql/src/tools/msvc:
ecpg_regression.proj (r1.1 -> r1.2)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/tools/msvc/ecpg_regression.proj?r1=1.1&r2=1.2)