Adding repository filter

[Hanstad]

Adding repository filter to control which repositories this plugin affects.

[DarthFennec]

Hi, thanks for contributing! My apologies that it took so long to respond to this.

First, I noticed that your file has DOS (CRLF) line endings, and the original file has Unix (LF) line endings. This makes the diff ('Files Changed' tab) hard to read, since it thinks there are no lines in common. Since all the plugins here use Unix line endings, it's best to stick to that.

As for the code, it looks pretty good to me. My one concern is that if the properties file doesn't exist, it throws an exception. I think for backwards compatibility, it would be better if it selected all repositories if no file exists, same as it does with an empty repository list.

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
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[yashprit-jfrog]

Closing PR because its been inactive since a long time & contribution is on deprecated plugin.