incorrect printout for multi-block DSIDs

A minor issue, but I just came across a case in !765 (merged) where I submitted two JOs, one for a physics block and one for the validation block and the commit script ended up saying:

The following DSIDs have been assigned:
	100xxx/100000 -> 950xxx/950098
	100xxx/100001 -> 500xxx/500332
Run: ./scripts/commit_new_dsid.sh -d=950098-500332 -m="aMC@NLOPy8 triphoton setups for PMG pub note" to push them to git

Note the range being suggested for the -d flag 😅