Slightly loosen exodiff tolerance for fixed point, nonlinear test
Slightly loosen exodiff tolerance for fixed point, nonlinear test

Refs CIVET failure [here](https://civet.inl.gov/job/938512/) and the
original PR #13033

idaholab/moose,milljm/moose,lindsayad/moose,sapitts/moose,harterj/moose,lindsayad/moose,dschwen/moose,laagesen/moose,bwspenc/moose,harterj/moose,nuclear-wizard/moose,bwspenc/moose,jessecarterMOOSE/moose,lindsayad/moose,jessecarterMOOSE/moose,jessecarterMOOSE/moose,andrsd/moose,dschwen/moose,bwspenc/moose,milljm/moose,idaholab/moose,idaholab/moose,harterj/moose,sapitts/moose,dschwen/moose,nuclear-wizard/moose,andrsd/moose,harterj/moose,dschwen/moose,idaholab/moose,laagesen/moose,laagesen/moose,sapitts/moose,bwspenc/moose,jessecarterMOOSE/moose,sapitts/moose,andrsd/moose,harterj/moose,laagesen/moose,andrsd/moose,idaholab/moose,sapitts/moose,dschwen/moose,milljm/moose,milljm/moose,jessecarterMOOSE/moose,bwspenc/moose,nuclear-wizard/moose,milljm/moose,nuclear-wizard/moose,lindsayad/moose,andrsd/moose,laagesen/moose,lindsayad/moose