Circumvent a bug in Trilinos 11.10

If we avoid calling GlobalAssemble when copying from an Epetra_FECrsMatrix that uses a
non-local matrix (enabled for Trilinos 11.9 and greater), we do not run into some bad
code in Trilinos causing a segfault. At this point of the code, it is enough if we only
call FillComplete because there should be no communication after all.