pgsql: Remove unnecessary logo output from msbuild when cleaning ecpg

Log Message:
-----------
Remove unnecessary logo output from msbuild when cleaning ecpg regression
test outputs.

Modified Files:
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pgsql/src/tools/msvc:
clean.bat (r1.8 -> r1.9)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/tools/msvc/clean.bat?r1=1.8&r2=1.9)