ODFTOOLKIT-437 validator: add -m flag for MathML schema

It turns out that the flags that were added in
cebaca9f710a9a06e177c6e80eb87d9e5c6c8c0c are not enough:

If the package contains a MathML embedded object, a null pointer
exception occurs, because the ODFValidator class assumes that either
all schemas are passed into its constructor as a Configuration,
or none of them are.

-M would be more appropriate, but it's already used, so use -m.
1 file changed