Skip Guard in IGF Solver (Revert ECP-WarpX#5284)

This reverts the inclusion of the guard cells when copying
rho. We could not yet determine why, but with this change
the FFT 3D solver in ImpactX does not converge to the
analytical solutions anymore.

Source/ablastr/fields/IntegratedGreenFunctionSolver.cpp

@@ -121,7 +121,7 @@ computePhiIGF ( amrex::MultiFab const & rho,
 
     BL_PROFILE_VAR_START(timer_pcopies);
     // Copy from rho including its ghost cells to tmp_rho
-    tmp_rho.ParallelCopy( rho, 0, 0, 1, rho.nGrowVect(), amrex::IntVect::TheZeroVector() );
+    tmp_rho.ParallelCopy( rho, 0, 0, 1, amrex::IntVect::TheZeroVector(), amrex::IntVect::TheZeroVector() );
     BL_PROFILE_VAR_STOP(timer_pcopies);
 
 #if !defined(ABLASTR_USE_HEFFTE)