Update lsf module to avoid using -N with -g option

[dawson6]

If a test case has nn=2 or some other nn option specified, and uses the ATS 'lrun' option, ats gives lrun a line like so:

lrun -N2 -n4 -g1 -c1 --pack

for example. But lrun states that -N2 and -g and the --pack options conflict, it does generate a line anyway.

In practice the generated line causes gpu issues and the code crashes.

Update the lrun module such that if running lrun with the -pack option to ignore the -nn option. Perhaps print a notice taht we are ignoring this.