How to deal with typo "2" instead of "2.1" for "GNU Lesser General Public" in headers?

[Friedrich W. H. Kossebau]

Happy New Year, all,

though I just made a not too happy discovery:
there are quite some files in the Calligra codebase which have a somehow 
broken license header which names the "GNU Lesser General Public" in "version 
2 of the License"...
which does not exist, there is only 2.1 as minimum version (2 was the version 
of the "Library" variant).

Seems someone once adapted the header from "GNU Library General Public" to 
"GNU Lesser General Public" but forgot the license number, and then people 
happily copied that header over since ages without noticing. Only a few files 
have a correct "GNU Lesser General Public" header.

Question:
can it be assumed (and should we) that all contributors actually agreed to the 
"2.1" version of the "Lesser" given there is no "2" version?
Especially as at least all files I checked also contain "or (at your option) 
any later version.", where "2.1" would be a theoretical later version of "2"?

To be on the really safe side I guess one would need to get all contributors 
explicitely agree to the correct version. But pragmatically I would just 
assume people very much were in agreement with 2.1, and this can be considered 
just a typo.

So would anyone strongly advise against simply applying a patch to all those 
license headers and change the "2" to "2.1"?

Cheers
Friedrich