DERBY-590: Eliminate some file-closure race conditions by explicitly closing the stream from which index properties are read; commit derby-590-17-aa-closeInputStreamOnPropertiesFile.diff.

git-svn-id: https://svn.apache.org/repos/asf/db/derby/code/trunk@1584859 13f79535-47bb-0310-9956-ffa450edef68