Fix for dynamic changes to GRES

If the GRES is associated with specific files AND
the GRES count is reset using scontrol AND
the slurmd is restarted either without a gres.conf file or with a count and no specific files AND
the GRES count is then increased using scontrol the GRES bitmap will not match its count

This fixes the root cause of the mismatch between bitmap size and GRES
count and should render the rebuilding of the bitmap unnecessary.
The rebuilding was handled in the following commits
commit ec4df3bf
commit 1712d619