bug#72267: automake 1.17 issue with new AM_SILENT_RULES

[Karl Berry]

    nb> there must be an expansion written somewhere in configure.ac
    which is producing the problematic construct.

Thanks Nick.

Francis, can you show us your configure.ac please?

    But at the same time, it is probably not a big deal to restore the
    extra newline in Automake.  But maybe use m4_newline() to make it
    extremely obvious that it was put there on purpose.

Ack. Thanks.

(Unfortunately it will be some time before I can get back to Automake.
If anyone else wants to jump in with patches, so much the better.)

Karl