Changes

docs: fix authors line exceeding the page

Fix that the authors get cut off as they exceed the page in the PDF
version. This can currently be seen here:
https://downloads.osmocom.org/docs/pysim/master/osmopysim-usermanual.pdf

Change-Id: Iacbba6c2f74bf2b9f96057e71bde017a11f703a8