Carry through the library FDIC when logging on to SYSSEC

Prior to the NSC FDIC change allowing the FDIC definition at a library level, we had bespoke code to set an FDIC. When we logged on to SYSDIC and SYSSEC, the FDIC of the previous library was carried through to either SYSDIC or SYSSEC using calls to USR3003N. This continues to work for SYSDIC but for SYSSEC it fails, saying '802 Access to FDIC denied; Library FDIC is preset'. this means the only way to link files to the relevant library is toinitiate Natural with a hardcoded FDIC. Ideally we would likeboth SYSSEC and SYSDIC to carry through the library FDIC as per NSC...