Increase file descriptor limit

[S81D]

When running the LoadANNIEEvent tool, which loads ANNIEEvents from the processed part files, it's been noticed that the tool fails to execute when including > ~1020 part files due to Linux's file descriptor limit. The tool runs smoothly until it reaches this limit, where it encounters an error like this:

[1]: LoadANNIEEvent: Loading new file /pnfs/annie/persistent/processed/processed_EBV2//R4783/ProcessedData_PMTMRDLAPPD_R4783S0p1017
[1]: LoadANNIEEvent: Loading new file /pnfs/annie/persistent/processed/processed_EBV2//R4783/ProcessedData_PMTMRDLAPPD_R4783S0p1018
[1]: Error Bad Filename: Cannot open /pnfs/annie/persistent/processed/processed_EBV2//R4783/ProcessedData_PMTMRDLAPPD_R4783S0p1019
[1]: LoadANNIEEvent: Loading new file /pnfs/annie/persistent/processed/processed_EBV2//R4783/ProcessedData_PMTMRDLAPPD_R4783S0p1019
[0]: LoadANNIEEvent: Filename /pnfs/annie/persistent/processed/processed_EBV2//R4783/ProcessedData_PMTMRDLAPPD_R4783S0p1019 not found! Proceed to next file

--> Warning errors in this tool and any other downstream tools, failure to load ANNIEEvents to the store

As this tool is frequently ran over all part files within a run, and we routinely have more than 1024 part files per run, I have included an increase in the file descriptor (4096) to Setup.sh. I have tested it and it alleviates the problem.