Bug#1135679: mumps: CeCILL-C license is not DFSG-compatible

[Drew Parsons]

Source: mumps
Followup-For: Bug #1135679
Control: severity -1 important

The question about CeCILL-C has been raised, but we don't have a
definitive declaration confirming incompatibility and requiring the
package to be ejected from Debian.  Let's not set the bug RC critical
before then.

The home of the licence is https://cecill.info/
( https://cecill.info/index.en.html )

FSF acknowledges CeCILL-C as Free,
https://www.gnu.org/licenses/license-list.html#CeCILL-C
We are not talking about a non-free licence here.

It is known to be GPL incompatible.
But that is not the same as LGPL incompatible.