Missing space in example

[Yves Savourel <ysavourel@enlaso.com>]

In the first example of section 2.7.2.6 Editing Hints:
There is a space missing at the end of the source content of the first segment (otherwise the two sentences would be against each
other).
In general I would recommend that all examples with more than one segment per unit be looked at for missing whitespace. It's easy to
forget them when writing examples manually.

-ys