Allow the use of a wider range of MUMPS versions

Currently, TELEMAC displays a warning when an untested version of MUMPS is used, the tested versions being only 4.10 and 5.2.1. Since TELEMAC is supposed to work with version 4.10, in practice it should work with all subsequent versions, some of which have in fact been tested (such as 5.4, 5.5 and 5.6). The warning should therefore only be displayed for versions below 4.10.